June 2017 - ghc-tickets

[GHC] #12545: Compilation time/space regression in GHC 8.0/8.1 (search in type-level lists and -O)
by GHC 13 Jun '17

13 Jun '17

#12545: Compilation time/space regression in GHC 8.0/8.1 (search in type-level lists and -O) -------------------------------------+------------------------------------- Reporter: | Owner: mikhail.vorozhtsov | Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- After upgrading to GHC 8.0.1 I've noticed that compilation time of one of my libraries got unacceptably long. Please find the attached test case. Here are some numbers from my machine: {{{ $ time ~/Prefixes/ghc-7.10.3/bin/ghc -O -c -Rghc-timing TypeList.hs Regression.hs <<ghc: 19103924976 bytes, 1441 GCs, 73048470/256579104 avg/max bytes residency (18 samples), 542M in use, 0.000 INIT (0.002 elapsed), 14.163 MUT (14.257 elapsed), 5.707 GC (5.830 elapsed) :ghc>> real 0m20.160s user 0m19.937s sys 0m0.197s $ time ~/Prefixes/ghc-8.0.1/bin/ghc -O -c -Rghc-timing TypeList.hs Regression.hs <<ghc: 147662211104 bytes, 9635 GCs, 190336418/433097448 avg/max bytes residency (38 samples), 1210M in use, 0.000 INIT (0.001 elapsed), 101.707 MUT (101.840 elapsed), 27.907 GC (28.259 elapsed) :ghc>> real 2m10.195s user 2m9.773s sys 0m0.400s }}} Both versions are the official Debian 8 x86_64 binaries from haskell.org. I also compiled the git master and unfortunately it is affected as well. It is worth mentioning that turning off optimization makes the problem disappear: {{{ $ time ~/Prefixes/ghc-8.0.1/bin/ghc -O0 -c -Rghc-timing TypeList.hs Regression.hs <<ghc: 3779057184 bytes, 225 GCs, 17923355/81566792 avg/max bytes residency (8 samples), 164M in use, 0.000 INIT (0.001 elapsed), 2.847 MUT (2.941 elapsed), 0.553 GC (0.572 elapsed) :ghc>> real 0m3.593s user 0m3.507s sys 0m0.073s }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12545> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13814: Unable to resolve instance for polykinded superclass constraint on associated-type-family.
by GHC 12 Jun '17

12 Jun '17

#13814: Unable to resolve instance for polykinded superclass constraint on associated-type-family. -------------------------------------+------------------------------------- Reporter: isovector | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: polykinds, | Operating System: Unknown/Multiple type families | Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following program doesn't compile: {{{#!hs {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE TypeFamilies #-} module Test where class Back k class Back (FrontBack k) => Front k where type FrontBack k :: k' instance Back Bool instance Front Int where type FrontBack Int = Bool }}} with the error message: {{{ • No instance for (Back (FrontBack Int)) arising from the superclasses of an instance declaration • In the instance declaration for ‘Front Int’ }}} The example successfully compiles if the kind annotation on FrontBack is removed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13814> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13816: make phase1 fails with clang error on Mac OS X El Capitan
by GHC 12 Jun '17

12 Jun '17

#13816: make phase1 fails with clang error on Mac OS X El Capitan -------------------------------------+------------------------------------- Reporter: bollu | 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: -------------------------------------+------------------------------------- `make` fails with the following build output at phase1: {{{ ╭─bollu@cantordust ~/work/ghc-all/ghc/libraries ‹2.3.1› ‹master*› ╰─$ export CC=gcc; export CXX=g++; CC=gcc CXX=g++ make 130 ↵ /Applications/Xcode.app/Contents/Developer/usr/bin/make -C .. all_libraries ===--- building phase 0 /Applications/Xcode.app/Contents/Developer/usr/bin/make --no-print- directory -f ghc.mk phase=0 phase_0_builds make[2]: Nothing to be done for `phase_0_builds'. ===--- building phase 1 /Applications/Xcode.app/Contents/Developer/usr/bin/make --no-print- directory -f ghc.mk phase=1 phase_1_builds utils/unlit/ghc.mk:33: utils/unlit/dist/build/.depend.c_asm: No such file or directory utils/hp2ps/ghc.mk:43: utils/hp2ps/dist/build/.depend.c_asm: No such file or directory utils/genapply/ghc.mk:23: utils/genapply/dist/build/.depend.haskell: No such file or directory utils/genapply/ghc.mk:23: utils/genapply/dist/build/.depend.c_asm: No such file or directory libraries/hpc/ghc.mk:3: libraries/hpc/dist-boot/build/.depend-v.haskell: No such file or directory libraries/hpc/ghc.mk:3: libraries/hpc/dist-boot/build/.depend-v.c_asm: No such file or directory libraries/binary/ghc.mk:3: libraries/binary/dist- boot/build/.depend-v.haskell: No such file or directory libraries/binary/ghc.mk:3: libraries/binary/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/Cabal/Cabal/ghc.mk:3: libraries/Cabal/Cabal/dist- boot/build/.depend-v.haskell: No such file or directory libraries/Cabal/Cabal/ghc.mk:3: libraries/Cabal/Cabal/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/ghc-boot-th/ghc.mk:3: libraries/ghc-boot-th/dist- boot/build/.depend-v.haskell: No such file or directory libraries/ghc-boot-th/ghc.mk:3: libraries/ghc-boot-th/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/ghc-boot/ghc.mk:3: libraries/ghc-boot/dist- boot/build/.depend-v.haskell: No such file or directory libraries/ghc-boot/ghc.mk:3: libraries/ghc-boot/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/template-haskell/ghc.mk:3: libraries/template-haskell/dist- boot/build/.depend-v.haskell: No such file or directory libraries/template-haskell/ghc.mk:3: libraries/template-haskell/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/hoopl/ghc.mk:3: libraries/hoopl/dist- boot/build/.depend-v.haskell: No such file or directory libraries/hoopl/ghc.mk:3: libraries/hoopl/dist-boot/build/.depend-v.c_asm: No such file or directory libraries/transformers/ghc.mk:3: libraries/transformers/dist- boot/build/.depend-v.haskell: No such file or directory libraries/transformers/ghc.mk:3: libraries/transformers/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/text/ghc.mk:3: libraries/text/dist-boot/build/.depend-v.haskell: No such file or directory libraries/text/ghc.mk:3: libraries/text/dist-boot/build/.depend-v.c_asm: No such file or directory libraries/terminfo/ghc.mk:3: libraries/terminfo/dist- boot/build/.depend-v.haskell: No such file or directory libraries/terminfo/ghc.mk:3: libraries/terminfo/dist- boot/build/.depend-v.c_asm: No such file or directory libraries/ghci/ghc.mk:3: libraries/ghci/dist-boot/build/.depend-v.haskell: No such file or directory libraries/ghci/ghc.mk:3: libraries/ghci/dist-boot/build/.depend-v.c_asm: No such file or directory compiler/ghc.mk:590: compiler/stage1/build/.depend-v.haskell: No such file or directory utils/ghc-pkg/ghc.mk:70: utils/ghc-pkg/dist/build/.depend.haskell: No such file or directory "rm" -f utils/ghc-pkg/dist/build/.depend.haskell.tmp "/usr/local/bin/ghc" -M -static -H32m -O -Wall -package-db libraries/bootstrapping.conf -hide-all-packages -i -iutils/ghc-pkg/. -iutils/ghc-pkg/dist/build -Iutils/ghc-pkg/dist/build -iutils/ghc- pkg/dist/build/ghc-pkg/autogen -Iutils/ghc-pkg/dist/build/ghc-pkg/autogen -optP-DWITH_TERMINFO -optP-include -optPutils/ghc-pkg/dist/build/ghc- pkg/autogen/cabal_macros.h -package-id base-4.9.1.0 -package-id directory-1.3.0.0 -package-id process-1.4.3.0 -package-id containers-0.5.7.1 -package-id filepath-1.4.1.1 -package-id Cabal-2.0.0.0 -package-id binary-0.8.4.1 -package-id ghc-boot-8.3 -package-id bytestring-0.10.8.1 -package-id terminfo-0.4.1.0 -package-id unix-2.7.2.1 -XHaskell2010 -no-user-package-db -rtsopts -odir utils/ghc- pkg/dist/build -hidir utils/ghc-pkg/dist/build -stubdir utils/ghc- pkg/dist/build -dep-makefile utils/ghc-pkg/dist/build/.depend.haskell.tmp -dep-suffix "" -include-pkg-deps utils/ghc-pkg/./Main.hs utils/ghc- pkg/dist/build/Version.hs utils/ghc-pkg/Main.hs:1451:40: error: error: editor placeholder in source file then termText (location db) <#> termText "\n (no packages)\n" ^ 1 error generated. `clang' failed in phase `C pre-processor'. (Exit code: 1) make[2]: *** [utils/ghc-pkg/dist/build/.depend.haskell] Error 1 make[1]: *** [all_libraries] Error 2 make: *** [all] Error 2 }}} g++ version: {{{ ╭─bollu@cantordust ~/work/ghc-all/ghc/libraries ‹2.3.1› ‹master*› ╰─$ g++ --version 2 ↵ Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 7.3.0 (clang-703.0.31) Target: x86_64-apple-darwin15.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin }}} GCC version: {{{ ╭─bollu@cantordust ~/work/ghc-all/ghc/libraries ‹2.3.1› ‹master*› ╰─$ gcc --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 7.3.0 (clang-703.0.31) Target: x86_64-apple-darwin15.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin }}} GHC version: {{{ ╭─bollu@cantordust ~/work/ghc-all/ghc/libraries ‹2.3.1› ‹master*› ╰─$ ghc --version The Glorious Glasgow Haskell Compilation System, version 8.0.2 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13816> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12582: HSOC Eventlog live profiling
by GHC 12 Jun '17

12 Jun '17

#12582: HSOC Eventlog live profiling -------------------------------------+------------------------------------- Reporter: NCrashed | Owner: NCrashed Type: feature | Status: new request | Priority: normal | Milestone: Component: Runtime | Version: 8.0.1 System | Keywords: eventlog | Operating System: Unknown/Multiple profile hsoc | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Hi, it is ticket for results of my Haskell Summer of Code 2016 project [1]. The goal is provide feature for redirection of events to external profilers without an application termination. Proposed changes: * Changing eventlog file descriptor in runtime. {{{#!c /* * Set custom file stream for global event log sink. * * The function overwrites previous event log file pointer. Previouss * sink is closed only if closePrev flag is on. * * Writing to the sink is protected by global mutex. * * The function puts header to the new sink only when emitHeader flag * is on. User might not want the header if it is switching to * already existed eventlog handle that was switched away recently. */ void rts_setEventLogSink(FILE *sink, StgBool closePrev, StgBool emitHeader); /* * Get current file stream that is used for global event log sink. * * You shouldn't do anything with the pointer until * rts_setEventLogSink(otherFileOrNull, false) is called. After that * you can do anything with the file stream. */ FILE* rts_getEventLogSink(void); }}} * Special flag `-lm` for RTS to store eventlog in memory chunks. User space functions to retrieve the chunks from memory. {{{#!c /* * If RTS started with '-lm' flag then eventlog is stored in memory buffer. * * The function allows to pop chunks of the buffer. Return value of 0 means * that there is no any filled chunk of data. * * If the function returns nonzero value the parameter contains full chunk * of eventlog data with size of the returned value. Caller must free the * buffer, the buffer isn't referenced anywhere anymore. * * If nobody calls the function with '-lm' flag then the memory is kinda * to be exhausted. */ StgWord64 rts_getEventLogChunk(StgInt8** ptr); }}} * Feature for dynamic resize of eventlog buffers. {{{#!c /* * Reallocate inner buffers to match the new size. The size should be not * too small to contain at least one event. * * If RTS started with '-lm' the chunks of memory buffer is also resized. */ void rts_resizeEventLog(StgWord64 size); /* * Return current size of eventlog buffers. */ StgWord64 rts_getEventLogBuffersSize(void); }}} * Bindings to new features in `Debug.Trace` in `base` package. {{{#!hs -- | The 'setEventLogCFile' function changes current sink of the eventlog, if eventlog -- profiling is available and enabled at runtime. -- -- The second parameter defines whether old sink should be finalized and closed or not. -- Preserving it could be helpful for temporal redirection of eventlog data into not -- standard sink and then restoring to the default file sink. -- -- The third parameter defines whether new header section should be emitted to the new -- sink. Emitting header to already started eventlog streams will corrupt the structure -- of eventlog format. -- -- The function is more low-level than 'setEventLogHandle' but doesn't recreate underlying -- file descriptor and is intended to use with 'getEventLogCFile' to save and restore -- current sink of the eventlog. -- -- @since 4.10.0.0 setEventLogCFile :: Ptr CFile -> Bool -> Bool -> IO () -- | The 'getEventLogCFile' function returns current sink of the eventlog, if eventlog -- profiling is available and enabled at runtime. -- -- The function is intented to be used with 'setEventLogCFile' to save and restore -- current sink of the eventlog. -- -- @since 4.10.0.0 getEventLogCFile :: IO (Ptr CFile) -- | Setting size of internal eventlog buffers. The size should be not -- too small to contain at least one event. -- -- If RTS started with '-lm' the chunks of memory buffer is also resized. -- -- The larger the buffers the lesser overhead from event logging, but -- larger delays between data dumps. -- -- See also: 'getEventLogChunk', 'getEventLogBufferSize' setEventLogBufferSize :: Word -> IO () -- | Getting size of internal eventlog buffers. -- -- See also: 'setEventLogBufferSize', 'getEventLogChunk' getEventLogBufferSize :: IO Word -- | Get next portion of the eventlog data. -- -- If RTS started with '-lm' flag then eventlog is stored in memory buffer. -- -- The function allows to pop chunks out of the buffer. Return value of Nothing -- means that there is no any filled chunk of data. -- -- If the function returns nonzero value the parameter contains full chunk -- of eventlog data with size of the returned value. Caller must free the -- buffer with 'free' from 'Foreign.Marshal.Alloc', the buffer isn't referenced -- anywhere anymore. -- -- If nobody calls the function with '-lm' flag on then the memory is kinda -- to be exhausted. -- -- If '-lm' flag is off, the function returns always 'Nothing'. -- -- See also: 'setEventLogBufferSize' getEventLogChunk :: IO (Maybe CStringLen) }}} References: 1. [http://ncrashed.github.io/blog/posts/2016-06-12-hsoc-acceptance.html HSOC project description] 2. [http://ncrashed.github.io/blog/posts/2016-06-22-hsoc-rts.html Design choices for implementation] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12582> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13811: eta reduction in GHCi for an educational purpose
by GHC 11 Jun '17

11 Jun '17

#13811: eta reduction in GHCi for an educational purpose -------------------------------------+------------------------------------- Reporter: vanto | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: GHCi | 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: -------------------------------------+------------------------------------- Hello,\\ Is it possible to have in GHCi an eta reduction of an expression for an educational purpose?\\ We would have access by typing a command like this on the line {{{:eta reduction <expr>}}} with the following annotation {{{show the eta reduction of <expr>}}} in short {{{:er <expr>}}}.\\ example:\\ {{{ Prelude> length xs = foldl (\n _ -> n+1) 0 xs Prelude> :eta reduction length --or :er length length = foldl (\n _ -> n+1) 0 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13811> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6017: Reading ./.ghci files raises security issues
by GHC 10 Jun '17

10 Jun '17

#6017: Reading ./.ghci files raises security issues -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: #8248 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by taylorfausak): I understand that this is an old issue, GHCi has behaved like this forever, and the `-ghci-script` workaround exists. Nonetheless this behavior always surprises and annoys me. Even if I run `chmod g-w .ghci` GHCi still complains that `. is writable by someone else` and ignores my `.ghci` file. I would like it if this permission check didn't exist at all, especially for directories and doubly so for `~/.ghci`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6017#comment:19> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13801: Make -main-is work with {thing} from arbitrary installed packages
by GHC 10 Jun '17

10 Jun '17

#13801: Make -main-is work with {thing} from arbitrary installed packages -------------------------------------+------------------------------------- Reporter: SimonHengel | Owner: (none) Type: feature | Status: new request | 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: -------------------------------------+------------------------------------- = TL;DR Conceptually, `-main-is {thing}` is useful when writing unit tests. It allows you to test the code in your "Main" module by allowing you to use a different name for it. But using it that way will always result in double compilation (that is, all your code has to be compiled twice, once for your executable and once for your test suite). The reason for this is that `{thing}` has to be part of the currently compiled package (aka the `main` package). As a consequent, when using `-is-main`, it is not possible to define a library that is used by both the executable and the test suite. I propose that `-main-is` is extended so that `{thing}` can be from any ''installed package''. I'll give a somewhat detailed motivation below. Please feel free to fast- forward to the last section, which gives a test case (or rather acceptance criteria) for this feature request. = The full story == How to unit test code without the use of {{{-main-is}}} This section shows a common way to structure code for an executable, so that it is possible to: 1. write unit tests for all the code 1. avoid double compilation between the executable and the test suite (for the reminder of this text I call these two properties ''desirable properties'') === Code as a library Define all your code outside of `Main`, including your `main` function. As an example, let's assume we define our code in `src/My/Awesome/Tool.hs`, which defines the module `My.Awesome.Tool` and a "main" function named `run` in it: {{{#!hs -- src/My/Awesome/Tool.hs module My.Awesome.Tool where run :: IO () run = do ... }}} === Tests that use the library It is then possible to write tests for that code by importing the library module, e.g.: {{{#!hs -- test/Main.hs module Main where imports My.Awesome.Tool main = do -- unit tests go here ... }}} === Executable as a thin wrapper around the library code To compile an actual executable we create a ''driver''. The driver imports the library module and defines a `main` function. For our example this would looks something like this: {{{#!hs -- driver/Main.hs module Main where import My.Awesome.Tool (run) main = run }}} '''Note:''' The driver does not define any non-trivial code. This is to retain our first desirable property. === Compiling everything with Cabal It is then possible to compile everything with Cabal, using a Cabal file similar to this one: {{{ -- my-awesome-tool.cabal name: my-awesome-tool library hs-source-dirs: src exposed-modules: My.Awesome.Tool test-suite test type: exitcode-stdio-1.0 build-depends: my-awesome-tool hs-source-dirs: test main-is: Main.hs executable my-awesome-tool build-depends: my-awesome-tool hs-source-dirs: driver main-is: Main.hs }}} '''Note:''' Both, the executable and the test suite depend on the library component. This avoids double compilation, one of our desirable properties. == Removing the need for a driver by using `-main-is` It is possible to get rid of the need for a driver by using `-main-is`: {{{ -- my-awesome-tool.cabal ... executable my-awesome-tool hs-source-dirs: src main-is: My/Awesome/Tool.hs ghc-options: -main-is My.Awesome.Tool.run }}} But doing so results in double compilation: The executable can no longer depend on the library component. This is expected behavior, as stated in the documentation: > Strictly speaking, `-main-is` is not a link-phase flag at all; it has no effect on the link step. The flag must be specified when compiling the module containing the specified main function == Shortcomings of `-main-is` According to the documentation, the purpose of `-main-is` is: > When testing, it is often convenient to change which function is the “main” one, and the `-main-is` flag allows you to do so. It is not very explicit what "when testing" refers to here, but for the lack of any other evidence I assume this refers to unit testing. As far as I can tell, there is no way to use `-main-is` for unit testing without double compilation. '''Or in other words:''' If we use `-main-is` for it's stated purpose we always loose the second of our desirable properties. Please correct me if you think that I'm wrong. == How is `-main-is` implemented? I haven't looked at any code, but my assumption is that GHC generates a driver module, similar to the one we have to write by hand if we don't use `-main-is`. Can somebody confirm (or negate) this? == Proposed change I propose that GHC always generates the driver when `-main-is {thing}` is specified. GHC should even generate the driver if `{thing}` is not part of the currently compiled package (specifically `{thing}` is defined in an ''installed package'', not the `main` package). == (manual) test case This test case uses my `hpack` package (but any package that defines some function of type `IO ()` should work): {{{ $ cabal install hpack $ ghc -package hpack -main-is Hpack.main -o hpack }}} === expected result An executable named `hpack` is compiled that uses `Hpack.main` from the installed package `hpack` as entry point. === actual result {{{ ghc: no input files Usage: For basic information, try the `--help' option. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13801> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13800: ghc panic: No skolem info: s_a7aK[sk]
by GHC 09 Jun '17

09 Jun '17

#13800: ghc panic: No skolem info: s_a7aK[sk] -------------------------------------+------------------------------------- Reporter: hexo | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Project is located at: https://github.com/hacxman/clock.git Uses Ivory and Tower framerworks. Error should be introduced by code in commit SSD1306 api wrapper ( https://github.com/hacxman/clock/commit/8075047381e3bcc572c2c12ccf83fd9410e… ) in file src/Clock/SSD1306.hs lines 32-67. When I run make blink-test, this happens: stack build . --exec 'blink-test-gen --src-dir=build/blink-test --const- fold --verbose' clock-0.1.0.0: build Preprocessing library clock-0.1.0.0... [5 of 7] Compiling Clock.SSD1306 ( src/Clock/SSD1306.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.2.0/build/Clock/SSD1306.o ) /home/mzatko/src/embedded/clock/src/Clock/SSD1306.hs:241:11: error:ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): No skolem info: s_a7aK[sk] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- While building package clock-0.1.0.0 using: /home/mzatko/.stack/setup-exe-cache/x86_64-linux/setup-Simple- Cabal-1.24.2.0-ghc-8.0.2 --builddir=.stack- work/dist/x86_64-linux/Cabal-1.24.2.0 build lib:clock exe:blink-test-gen exe:oled-test-gen --ghc-options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 Makefile:50: recipe for target 'blink-test' failed make: *** [blink-test] Error 1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13800> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13806: Invalid usage of TypeFamilies cause GHC Internal Error
by GHC 09 Jun '17

09 Jun '17

#13806: Invalid usage of TypeFamilies cause GHC Internal Error -------------------------------------+------------------------------------- Reporter: utdemir | Owner: (none) Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | error/warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I couldn't be able to reproduce this with a valid program, but seeing "GHC internal error" was surprising. Only the second error should be enough in this case. {{{ $ cat test.hs {-# LANGUAGE TypeFamilies #-} data Foo value = Foo (T value) class Cl t where type T mk :: t -> T main :: IO () main = undefined $ runhaskell test.hs test.hs:4:10: error: • GHC internal error: ‘T’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [a10K :-> Type variable ‘value’ = value, r10F :-> ATcTyCon Foo, r10G :-> APromotionErr RecDataConPE] • In the type ‘T value’ In the definition of data constructor ‘Foo’ In the data declaration for ‘Foo’ test.hs:6:1: error: • The associated type ‘T’ mentions none of the type or kind variables of the class ‘Cl t’ • In the class declaration for ‘Cl’ $ runhaskell --version runghc 8.0.2 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13806> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13802: Installation of yesod-auth-1.4.13.2 fails with "ghc: panic! (the 'impossible' happened)"
by GHC 08 Jun '17

08 Jun '17

#13802: Installation of yesod-auth-1.4.13.2 fails with "ghc: panic! (the 'impossible' happened)" -------------------------------------+------------------------------------- Reporter: nvbt | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: panic, stack, | Operating System: MacOS X install | Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I wanted to install hledger-web via "stack install hledger-web" which runs until it hits (this is the full output of the command, emphasis [+] was added): {{{ yesod-auth-1.4.13.2: configure yesod-auth-1.4.13.2: build Progress: 1/3 -- While building package yesod-auth-1.4.13.2 using: /Users/manuel/.stack/setup-exe-cache/x86_64-osx/Cabal- simple_mPHDZzAJ_1.22.5.0_ghc-7.10.3 --builddir=.stack- work/dist/x86_64-osx/Cabal-1.22.5.0 build --ghc-options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 Logs have been written to: /Users/manuel/.stack/global-project/.stack- work/logs/yesod-auth-1.4.13.2.log Configuring yesod-auth-1.4.13.2... Building yesod-auth-1.4.13.2... Preprocessing library yesod-auth-1.4.13.2... [ 1 of 12] Compiling Yesod.PasswordStore ( Yesod/PasswordStore.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Yesod/PasswordStore.o ) /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/PasswordStore.hs:166:31: Warning: Defaulting the following constraint(s) to type ‘Integer’ (Integral b0) arising from a use of ‘^’ at Yesod/PasswordStore.hs:166:31 (Num b0) arising from the literal ‘32’ at Yesod/PasswordStore.hs:166:32-33 In the first argument of ‘(-)’, namely ‘2 ^ 32’ In the first argument of ‘(*)’, namely ‘(2 ^ 32 - 1)’ In the second argument of ‘(>)’, namely ‘(2 ^ 32 - 1) * hLen’ /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/PasswordStore.hs:419:1: Warning: Defined but not used: ‘toStrict’ /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/PasswordStore.hs:422:1: Warning: Defined but not used: ‘fromStrict’ [ 2 of 12] Compiling Yesod.Auth.Message ( Yesod/Auth/Message.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Yesod/Auth/Message.o ) /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/Auth/Message.hs:23:1: Warning: The import of ‘mappend’ from module ‘Data.Monoid’ is redundant /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/Auth/Message.hs:698:1: Warning: Defined but not used: ‘croatianMessage’ /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/Auth/Message.hs:459:1: Warning: Pattern match(es) are overlapped In an equation for ‘finnishMessage’: finnishMessage Password = ... /private/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/stack34153 /yesod-auth-1.4.13.2/Yesod/Auth/Message.hs:459:1: Warning: Pattern match(es) are non-exhaustive In an equation for ‘finnishMessage’: Patterns not matched: CurrentPassword [ 3 of 12] Compiling Yesod.Auth.Routes ( Yesod/Auth/Routes.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Yesod/Auth/Routes.o ) [ 4 of 12] Compiling Yesod.Auth ( Yesod/Auth.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Yesod/Auth.o ) [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++] ghc: panic! (the 'impossible' happened) (GHC version 7.10.3 for x86_64-apple-darwin): Loading temp shared object failed: dlopen(/var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/ghc34454_0/libghc_21.dylib, 5): no suitable image found. Did find: /var/folders/36/cmdfg5j90vjgjww3qjnvhkhw0000gn/T/ghc34454_0/libghc_21.dylib: malformed mach-o: load commands size (35400) > 32768 [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} I have tried this installation multiple times over the last weeks, and have always failed with this error message. If any further assistance is needed I will be happy to help. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13802> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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