On 6 June 2017 at 21:13, Henk-Jan van Tuyl wrote:

You are right, versionBranch is from originally from base, but you are missing the point: package wxc compiles perfectly the first time, but, without anything being changed, does not compile the second time. By the way, I am using a cabal sandbox and as I said earlier, I am using a GHC release candidate.

And in that release candidate, does the version of base have versionBranch in it? My guess is that a new version of Cabal is being used the second time, which is compiled against the base that comes with that RC which is missing versionBranch. (But since I don't have any GHC RC's I can't check it myself.)

Regards, Henk-Jan van Tuyl

On Tue, 06 Jun 2017 00:33:40 +0200, Ivan Lazar Miljenovic wrote:

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On 6 June 2017 at 07:55, Henk-Jan van Tuyl wrote:

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wxc/setup.hs uses versionBranch from Cabal[0]; the function versionBranch is not in Cabal 2, that is why I added "Cabal < 2" to wxc.cabal. When installing wxc the first time, the right version of Cabal is picked, when "cabal install" is invoked a second time, GHC tries to compile wxc/setup.hs again, but with the wrong version of Cabal (note: the release candidate of GHC comes with Cabal 2)

[0]

https://hackage.haskell.org/package/Cabal-1.24.2.0/docs/Distribution-Make.ht...

If you look at the source for this module, you'll see that it isn't defined in there; it's actually from Data.Version in base.

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On Mon, 05 Jun 2017 04:58:05 +0200, Ivan Lazar Miljenovic wrote:

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I don't think it's a problem with Cabal, but the version of base going by the error: versionBranch is from base, and that error message is talking about compiling the setup.hs from wxc.

On 5 June 2017 at 12:03, Henk-Jan van Tuyl wrote:

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The strange thing is, that the right version of Cabal is picked, the first time wxc is compiled. But when invoking cabal-install the second time, the setup-depends section seems to be ignored (or at least the Cabal < 2 part). This does not happen with GHC 8.0.2

(By the way, cabal-install tries to compile setup.hs again, even though nothing has changed.)

Regards, Henk-Jan van Tuyl

On Sun, 04 Jun 2017 13:39:17 +0200, Ivan Lazar Miljenovic wrote:

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This is from a limitation/bug with Cabal-the-library, in that there are typically no dependency checks for custom Setup.[l]hs configurations.

wxc has such a custom one: http://hackage.haskell.org/package/wxc-0.92.3.0/src/Setup.hs

versionBranch is from Data.Version in base, and it appears that the in this GHC pre-release there's been a change in base that removed this function.

On 4 June 2017 at 19:45, Henk-Jan van Tuyl wrote: > > > > > L.S., > > I am trying the prerelease of GHC, version 8.2.0.20170507 > > I adapted wxHaskell to the new packages that come with the new GHC > and > it > compiles now, but only the first time. If I compile it a second time, > even > if nothing has changed, the information from the custom-setup section > of > the wxc.cabal file seems to be forgotten. This section looks like > this: > > custom-setup > setup-depends: > base, > Cabal < 2, > containers, > bytestring, > split, > process, > directory, > filepath > (I am using cabal-install 1.24.0.2) > > Output from the second time I try to install wxHaskell: > >> cabal install --force-reinstalls --reinstall wxdirect wxc wxcore wx > > > > > [1 of 1] Compiling Main ( > X:\Temp\wxHaskell\wxcore\dist\setup\setup.hs, > X:\Temp\wxHaskell\wxcore\dist\setup\Main.o ) > Linking X:\Temp\wxHaskell\wxcore\dist\setup\setup.exe ... > [1 of 1] Compiling Main ( > X:\Temp\wxHaskell\wxc\dist\setup\setup.hs, > X:\Temp\wxHaskell\wxc\dist\setup\Main.o ) > > X:\Temp\wxHaskell\wxc\dist\setup\setup.hs:505:61: error: > Variable not in scope: versionBranch :: Version > -> > [a0] > | > 505 | full_ver = (concat . intersperse "." . map show . > versionBranch) ver > | > ^^^^^^^^^^^^^ > > This error message indicates that the wrong version of Cabal (2.0) is > used > to compile the wxcore setup.hs > It looks like a cabal-install bug, but this does not happen when I > use GHC 8.0.2; should I write a GHC bug ticket? > > Regards, > Henk-Jan van Tuyl

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