November 2017 - ghc-tickets

[GHC] #8542: Suggest NegativeLiterals
by GHC 13 Mar '18

13 Mar '18

#8542: Suggest NegativeLiterals ------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- If we write -128 :: Int8, we get a useful warning (#7895), but it would be even better to suggest NegativeLiterals. Patch incoming. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8542> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 9

[GHC] #13257: out-of-range warnings for negative literals, without -XNegativeLiterals
by GHC 12 Mar '18

12 Mar '18

#13257: out-of-range warnings for negative literals, without -XNegativeLiterals -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- By default (without `NegativeLiterals`) a negated literal `-1` is desugared as `negate (fromInteger 1)`. Hence the existing out-of-range literal warning doesn't trigger for `-1 :: Word`. But we could also recognize the pattern `negate (fromInteger lit)`, and give a warning when `-lit` is out-of-range (for `Word`, this is whenever `lit` is positive). Actually this could apply to signed integer types too: if we recognized `negate (fromInteger lit)` in preference to `fromInteger lit`, we could correctly not warn about `-128 :: Int8`, even when `NegativeLiterals` is not enabled. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13257> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #13366: addCStub doesn't allow control over compiler flags or source file file
by GHC 12 Mar '18

12 Mar '18

#13366: addCStub doesn't allow control over compiler flags or source file file -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Currently if you pass a C source file on the GHC command line you can control whether the compiler treats it as C or C++ via the it's extension: GCC will treat a file ending in `.c` as C, whereas `.cpp` is treated as C++. However, we currently have no means of controlling what language a stub added with in Template Haskell with `addCStub` will be treated as. Consequently it is currently impossible to compile a C++ source file with `addCStub` without using `-optc`. Moreover, you can't have mixed C/C++ stubs at all. It really seems like this interface should be amended to fix this before we release it in 8.2. Perhaps `addCStub` should accept both the source and a set of compiler flags which will be added to the usual flags (allowing one to pass `-x c++` to the compiler when compiling C++ files)? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13366> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 15

[GHC] #13543: Improve demand analysis for join points
by GHC 12 Mar '18

12 Mar '18

#13543: Improve demand analysis for join points -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider {{{ g :: (Int,Int) -> Int g (p,q) = p+q f :: Int -> Int -> Int f x p = g (join j y = (p,y) in case x of True -> j 3 False -> j 4) }}} If `j` was a vanilla function definition, we'd analyse its body with `evalDmd`, and think that it was lazy in `p`. But for a join point we can do better. We know that `j`'s body (if evaluated at all) will be evaluated with the demand that consumes the entire join-binding, in this case the argument demand from `g`. Whizzo! `g` evaluates both components of its arugment pair, so j is strict in `p`. So, when analysing a join point, we can analyse its body with the demand from the entire join-binding. Another win for join points! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13543> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

[GHC] #13844: Surprising behavior with CPP extension
by GHC 12 Mar '18

12 Mar '18

#13844: Surprising behavior with CPP extension -------------------------------------+------------------------------------- Reporter: deech | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The CPP language extension performs macro substitutions in Haskell comments. I see why it does but it seems like eliding the comments before pre-processing would be less surprising. Eg. compiling: {{{#!hs {-# LANGUAGE CPP -#} -- | Some folder foo/bar/* }}} gives the error: {{{ error: unterminated comment -- | Some folder foo/bar/* }}} because the `/*` in the comment is interpreted as starting a C comment. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13844> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #14372: CMM contains a bunch of tail-merging opportunities
by GHC 12 Mar '18

12 Mar '18

#14372: CMM contains a bunch of tail-merging opportunities -------------------------------------+------------------------------------- Reporter: heisenbug | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Compile this code to CMM {{{#!hs data Small = S1 | S2 | S3 | S4 deriving (Show, Enum) data Big = B1 | B2 | B3 | B4 | B5 | B6 | B7 | B8 | B9 | B10 deriving (Show, Enum) {-# NOINLINE quux #-} quux B1 = 'a' quux B2 = 'b' quux B3 = 'c' quux B4 = 'd' quux B5 = 'e' quux B6 = 'f' quux B7 = 'g' quux B8 = 'h' quux B9 = 'i' quux B10 = 'j' {-# NOINLINE qaax #-} qaax B1 = 'a' qaax B2 = 'b' qaax B3 = 'c' qaax B4 = 'd' qaax B5 = 'e' qaax B7 = 'g' qaax B8 = 'h' qaax B9 = 'i' qaax B10 = 'j' {-# NOINLINE foo #-} foo B1 = S1 foo B2 = S2 foo B3 = S3 foo B4 = S4 {-# NOINLINE bar #-} bar S1 = B1 bar S2 = B2 bar S3 = B3 bar S4 = B4 main = do print $ take 100000 (repeat (foo <$> [B1 .. B4])) print $ take 100000 (repeat (bar <$> [S1 .. S4])) print $ take 100000 (repeat (quux <$> [B1 .. B10])) print $ qaax B1 }}} When `Char` or ''enum-like'' ADT is returned, I see lots of case branches, which only differ in the first instruction. E.g. {{{ c30l: // global R1 = stg_CHARLIKE_closure+1649; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30m: // global R1 = stg_CHARLIKE_closure+1665; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; u30Z: // global if (_c30p::I64 < 9) goto c30n; else goto c30o; c30n: // global R1 = stg_CHARLIKE_closure+1681; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30o: // global R1 = stg_CHARLIKE_closure+1697; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; }}} It would be nice to factor out the common tails, e.g. by branching to the first tail already emitted. Bonus points for rewriting switch tables to contain the above numbers and compile to a lookup + common code. This is what I am talking about: {{{ c307: // global _s2ON::P64 = R1; _c30j::P64 = _s2ON::P64 & 7; switch [1 .. 7] _c30j::P64 { case 1 : goto c30d; case 2 : goto c30e; case 3 : goto c30f; case 4 : goto c30g; case 5 : goto c30h; ... } ... c30h: // global R1 = stg_CHARLIKE_closure+1617; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30g: // global R1 = stg_CHARLIKE_closure+1601; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30f: // global R1 = stg_CHARLIKE_closure+1585; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30e: // global R1 = stg_CHARLIKE_closure+1569; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; c30d: // global R1 = stg_CHARLIKE_closure+1553; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; }}} There should be an array [1553, 1569, 1585, ...] and each case should be the same: {{{ R1 = stg_CHARLIKE_closure; R1 = R1 + array[tag]; Sp = Sp + 8; call (P64[Sp])(R1) args: 8, res: 0, upd: 8; }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14372> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 22

[GHC] #13982: HEAD GHC+Cabal uses too much memory
by GHC 11 Mar '18

11 Mar '18

#13982: HEAD GHC+Cabal uses too much memory -------------------------------------+------------------------------------- Reporter: mniip | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: libraries | Version: 8.3 (other) | Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Runtime (amd64) | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- If you install GHC HEAD and bootstrap cabal "2.0.0.0" as submoduled in that, whenever installing any packages cabal will hang for minutes before dependency resolution and will eat about 10 gigabytes of memory. I did a simple profile, {{{ COST CENTRE MODULE SRC %time %alloc packageListFromCache.readPackageDescription Distribution.Client.IndexUtils Distribution/Client/IndexUtils.hs:(714,5)-(722,61) 95.7 99.4 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13982> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #14044: ghc-8.2.1 installation fails on OpenBSD 6.0
by GHC 11 Mar '18

11 Mar '18

#14044: ghc-8.2.1 installation fails on OpenBSD 6.0 -------------------------------------+------------------------------------- Reporter: | Owner: (none) romanzolotarev | Type: bug | Status: new Priority: normal | Milestone: Research needed Component: None | Version: 8.2.1 Keywords: | Operating System: OpenBSD Architecture: x86_64 | Type of failure: Installing GHC (amd64) | failed Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I have tried to install ghc-8.2.1 directly and via stack. Getting the same error: {{{ ghc-cabal: can't load library 'libc.so.89.3' }}} ghc requires 'libc.so.89.3', while OpenBSD 6.0 has 'libc.so.88.0' by default. {{{ # find / -name libc.so* /usr/lib/libc.so.88.0 /usr/lib/libc.so.88.0.a }}} ---- Full log {{{ # /root/.cabal/bin/stack setup Preparing to install GHC to an isolated location. This will not interfere with any system-level installation. Already downloaded. Running /usr/local/bin/gmake install in directory /root/.stack/programs/x86_64-openbsd/ghc-8.2.1.temp/ghc-8.2.1/ exited with ExitFailure 2 /usr/local/bin/gmake --no-print-directory -f ghc.mk install BINDIST=YES NO_INCLUDE_DEPS=YES "rm" -f utils/ghc-pkg/dist-install/build/Version.hs echo "module Version where" >> utils/ghc-pkg/dist- install/build/Version.hs echo "version, targetOS, targetARCH :: String" >> utils/ghc-pkg/dist- install/build/Version.hs echo "version = \"8.2.1\"" >> utils/ghc-pkg/dist- install/build/Version.hs echo "targetOS = \"openbsd\"" >> utils/ghc-pkg/dist- install/build/Version.hs echo "targetARCH = \"x86_64\"" >> utils/ghc-pkg/dist- install/build/Version.hs "rm" -f utils/ghc-pkg/dist/build/Version.hs echo "module Version where" >> utils/ghc- pkg/dist/build/Version.hs echo "version, targetOS, targetARCH :: String" >> utils/ghc- pkg/dist/build/Version.hs echo "version = \"8.2.1\"" >> utils/ghc-pkg/dist/build/Version.hs echo "targetOS = \"openbsd\"" >> utils/ghc- pkg/dist/build/Version.hs echo "targetARCH = \"x86_64\"" >> utils/ghc-pkg/dist/build/Version.hs /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'exeprog="hp2ps"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" cat utils/hp2ps/hp2ps.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hp2ps" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci-8.2.1" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci-8.2.1" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci-8.2.1" echo 'exec "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" --interactive "$@"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci-8.2.1" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci-8.2.1" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci" ln -s ghci-8.2.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghci" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/." && /usr/bin/install -c -m 644 includes/./*.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/./" && /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts" && /usr/bin/install -c -m 644 includes/rts/*.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts/" && /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts/prof" && /usr/bin/install -c -m 644 includes/rts/prof/*.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts/prof/" && /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts/storage" && /usr/bin/install -c -m 644 includes/rts/storage/*.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/rts/storage/" && /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/stg" && /usr/bin/install -c -m 644 includes/stg/*.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/stg/" && true /usr/bin/install -c -m 644 includes/ghcautoconf.h includes/ghcplatform.h includes/ghcversion.h includes/dist- derivedconstants/header/DerivedConstants.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include/" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'exeprog="haddock"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" cat utils/haddock/haddock.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock-ghc-8.2.1" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Classic.theme/" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/latex/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html /haddock-util.js "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/Classic.theme/haskell_icon.gif "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Classic.theme/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/Classic.theme/minus.gif "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Classic.theme/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/Classic.theme/plus.gif "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Classic.theme/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/Classic.theme/xhaddock.css "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Classic.theme/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html/Ocean .std-theme/hslogo-16.png "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html/Ocean .std-theme/minus.gif "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html/Ocean .std-theme/ocean.css "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html/Ocean .std-theme/plus.gif "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 644 utils/haddock/haddock-api/resources/html/Ocean .std-theme/synopsis.png "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/Ocean .std-theme/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/solarized.css "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/html/highlight.js "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/html/" /usr/bin/install -c -m 644 utils/haddock/haddock- api/resources/latex/haddock.sty "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/latex/" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock" ln -s haddock-ghc-8.2.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/haddock" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'exeprog="hsc2hs"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" echo 'HSC2HS_EXTRA="--cflag=-std=gnu99 --cflag=-fno-stack-protector --lflag=-Wl,-z,wxneeded"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" cat utils/hsc2hs/hsc2hs.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hsc2hs" /usr/bin/install -c -m 644 utils/hsc2hs/template-hsc.h "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'exeprog="ghc-pkg"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" cat utils/ghc-pkg/ghc-pkg.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg-8.2.1" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-pkg" ln -s ghc-pkg-8.2.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin /ghc-pkg" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'exeprog="hpc"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" cat utils/hpc/hpc.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/hpc" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'exeprog="runghc"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" echo 'ghcprog="ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" cat utils/runghc/runghc.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc-8.2.1" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runhaskell" ln -s runghc "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runhaskell" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc" ln -s runghc-8.2.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/runghc" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" create () { touch "$1" && chmod 755 "$1" ; } && create "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo '#!/bin/sh' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'exedir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'exeprog="ghc-stage2"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'executablename="$exedir/$exeprog"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'datadir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'bindir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'topdir="/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" echo 'executablename="$exedir/ghc"' >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" cat ghc/ghc.wrapper >> "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" chmod +x "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc-8.2.1" "rm" -f "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc" ln -s ghc-8.2.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/bin/ghc" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share/man" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share/man/man1" /usr/bin/install -c -m 644 docs/users_guide/build-man/ghc.1 "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share/man/man1" # driver/ghc-usage.txt driver/ghci-usage.txt includes/dist- derivedconstants/header/platformConstants settings = libraries to install # "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" = directory to install to # # The .dll case calls STRIP_CMD explicitly, instead of `install -s`, because # on Win64, "install -s" calls a strip that doesn't understand 64bit binaries. # For some reason, this means the DLLs end up non-executable, which means # executables that use them just segfault. /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" for i in driver/ghc-usage.txt driver/ghci-usage.txt includes/dist- derivedconstants/header/platformConstants settings; do case $i in *.a) /usr/bin/install -c -m 644 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"; true "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"/`basename $i` ;; *.dll) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" ; strip "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"/`basename $i` ;; *.so) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" ;; *.dylib) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1";; *) /usr/bin/install -c -m 644 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"; esac; done gcc -E -undef -traditional -P -DINSTALLING -DLIB_DIR='"/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1"' -DINCLUDE_DIR='"/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/include"' -DFFI_INCLUDE_DIR=/usr/local/include -DFFI_LIB_DIR=/usr/local/lib '-DFFI_LIB=' -x c -Iincludes -Iincludes/dist -Iincludes/dist- derivedconstants/header -Iincludes/dist-ghcconstants/header rts/package.conf.in -o rts/dist/package.conf.install.raw grep -v '^#pragma GCC' rts/dist/package.conf.install.raw | sed -e 's/""//g' -e 's/:[ ]*,/: /g' >rts/dist/package.conf.install /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin" for i in utils/unlit/dist/build/tmp/unlit utils/hp2ps/dist/build/tmp/hp2ps utils/hp2ps/dist/build/tmp/hp2ps utils/haddock/dist/build/tmp/haddock utils/haddock/dist/build/tmp/haddock utils/hsc2hs/dist- install/build/tmp/hsc2hs utils/hsc2hs/dist-install/build/tmp/hsc2hs utils /ghc-pkg/dist-install/build/tmp/ghc-pkg utils/ghc-pkg/dist- install/build/tmp/ghc-pkg utils/hpc/dist-install/build/tmp/hpc utils/hpc /dist-install/build/tmp/hpc utils/runghc/dist-install/build/tmp/runghc utils/runghc/dist-install/build/tmp/runghc ghc/stage2/build/tmp/ghc-stage2 ghc/stage2/build/tmp/ghc-stage2 iserv/stage2/build/tmp/ghc-iserv iserv/stage2_p/build/tmp/ghc-iserv-prof iserv/stage2_dyn/build/tmp/ghc- iserv-dyn; do \ /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin"; \ done "mv" "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin /ghc-stage2" "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/bin/ghc" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1" "rm" -rf "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/package.conf.d" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/package.conf.d" /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts" # rts/dist/build/libHSrts.a rts/dist/build/libHSrts_p.a rts/dist/build /libHSrts-ghc8.2.1.so rts/dist/build/libHSrts_l.a rts/dist/build/libHSrts_debug.a rts/dist/build/libHSrts_thr.a rts/dist/build/libHSrts_thr_debug.a rts/dist/build/libHSrts_thr_l.a rts/dist/build/libHSrts_thr_p.a rts/dist/build/libHSrts_debug-ghc8.2.1.so rts/dist/build/libHSrts_thr-ghc8.2.1.so rts/dist/build/libHSrts_thr_debug- ghc8.2.1.so rts/dist/build/libHSrts_l-ghc8.2.1.so rts/dist/build /libHSrts_thr_l-ghc8.2.1.so = libraries to install # "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts" = directory to install to # # The .dll case calls STRIP_CMD explicitly, instead of `install -s`, because # on Win64, "install -s" calls a strip that doesn't understand 64bit binaries. # For some reason, this means the DLLs end up non-executable, which means # executables that use them just segfault. /usr/bin/install -c -m 755 -d "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts" for i in rts/dist/build/libHSrts.a rts/dist/build/libHSrts_p.a rts/dist/build/libHSrts-ghc8.2.1.so rts/dist/build/libHSrts_l.a rts/dist/build/libHSrts_debug.a rts/dist/build/libHSrts_thr.a rts/dist/build/libHSrts_thr_debug.a rts/dist/build/libHSrts_thr_l.a rts/dist/build/libHSrts_thr_p.a rts/dist/build/libHSrts_debug-ghc8.2.1.so rts/dist/build/libHSrts_thr-ghc8.2.1.so rts/dist/build/libHSrts_thr_debug- ghc8.2.1.so rts/dist/build/libHSrts_l-ghc8.2.1.so rts/dist/build /libHSrts_thr_l-ghc8.2.1.so; do case $i in *.a) /usr/bin/install -c -m 644 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts"; true "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts"/`basename $i` ;; *.dll) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts" ; strip "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts"/`basename $i` ;; *.so) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts" ;; *.dylib) /usr/bin/install -c -m 755 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts";; *) /usr/bin/install -c -m 644 $i "/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1/rts"; esac; done "utils/ghc-cabal/dist-install/build/tmp/ghc-cabal-bindist" copy libraries /ghc-prim dist-install "strip" '' '/root/.stack/programs/x86_64-openbsd/ghc-8.2.1' '/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/lib/ghc-8.2.1' '/root/.stack/programs/x86_64-openbsd/ghc-8.2.1/share/doc/ghc-8.2.1/html/libraries' 'v p dyn' ghc-cabal: can't load library 'libc.so.89.3' gmake[1]: *** [ghc.mk:991: install_packages] Error 4 gmake: *** [Makefile:51: install] Error 2 Error: Error encountered while installing GHC with gmake install run in /root/.stack/programs/x86_64-openbsd/ghc-8.2.1.temp/ghc-8.2.1/ The following directories may now contain files, but won't be used by stack: - /root/.stack/programs/x86_64-openbsd/ghc-8.2.1.temp/ - /root/.stack/programs/x86_64-openbsd/ghc-8.2.1/ Installing GHC ... }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14044> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #14335: Annotations aren't supported with -fexternal-interpreter
by GHC 08 Mar '18

08 Mar '18

#14335: Annotations aren't supported with -fexternal-interpreter -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It seems that using `{-# ANN #-}` pragmas from a plugin cause GHC to crash when run with `-fexternal-interpreter` with {{{ ghc: this operation requires -fno-external-interpreter }}} It seems that the culprit is likely the use of `wormhole` in `convertAnnotationWrapper`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14335> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 17

[GHC] #12959: GHC doesn't warn about missing implementations for class methods beginning with an underscore
by GHC 08 Mar '18

08 Mar '18

#12959: GHC doesn't warn about missing implementations for class methods beginning with an underscore -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This code compiles without any warnings! {{{#!hs {-# OPTIONS_GHC -Wmissing-methods #-} module Bug where class Foo a where _Bar :: a -> Int instance Foo Int }}} This code, however, //does// emit a warning: {{{#!hs {-# OPTIONS_GHC -Wmissing-methods #-} module Warns where class Foo a where bBar :: a -> Int instance Foo Int }}} {{{ Bug.hs:7:10: warning: [-Wmissing-methods] • No explicit implementation for ‘bBar’ • In the instance declaration for ‘Foo Int’ }}} The only difference is in the name of the class method of `Foo`. Namely, when a class method is prefixed with an underscore, GHC seems to look the other way when checking if any instances are missing an implementation of it. I'd argue that this behavior is incorrect, since I can't envision any scenario in which you'd want the compiler //not// to warn you about missing method implementations (as opposed to, say, not warning about an unused record selector). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12959> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 12