cabal no longer supports package version tags

[bos]

(Imported from Trac #900, reported by guest on 2011-11-20)

The following cabal file below triggers an assertion fail on the second install:

$ cabal --version
cabal-install version 0.13.3
using version 1.13.3 of the Cabal library
$ cabal install
Resolving dependencies...
Configuring foobar-0.2.0...
Building foobar-0.2.0...
Preprocessing library foobar-0.2.0...
[1 of 1] Compiling FooBar           ( FooBar.hs, dist/build/FooBar.o )
[1 of 1] Compiling FooBar           ( FooBar.hs, dist/build/FooBar.p_o )
Registering foobar-0.2.0...
Installing library in /home/hvr/.cabal/lib/foobar-0.2.0/ghc-7.2.2
Registering foobar-0.2.0...
$ cabal install
Resolving dependencies...
Configuring foobar-0.2.0...
cabal: Distribution/Simple/PackageIndex.hs:123:8-13: Assertion failed

Only when I unregister the installed package via ghc-pkg unregister foobar I can configure the package again...

The cabal file causing this behaviour:

name:                foobar
version:             0.2.0-git20111120
synopsis:            none
license:             BSD3
license-file:        LICENSE
author:              foo
maintainer:          foo@bar
build-type:          Simple
cabal-version:       >=1.10
library
  default-language: Haskell2010
  exposed-modules: FooBar
  build-depends: base

The FooBar module is just a dummy empty module. This used to work previously, e.g. with

$ cabal-0.11.2  --version
cabal-install version 0.11.2
using version 1.12.0 of the Cabal library

[bos]

(Imported comment by @dcoutts on 2011-11-20)

Package version tags are no longer supported. We should make this explicit and fail up front with a better error message.

[ntc2]

I just ran into this. Very confusing, since I'd never heard of Cabal tags. I added a version to the version number documentation: http://www.haskell.org/haskellwiki/Package_versioning_policy#Warning.21.

If the solution is to not support tags on the front end, then the fix is simple: just edit

Data.Version.parseVersion

and remove support for parsing tags (source).

[ezyang]

We still don't warn if there is a tag in the version number.

[kolmodin]

At least hackage should reject packages using version tags.
https://github.com/haskell/hackage-server/blob/master/Distribution/Server/Packages/Unpack.hs

[linearray]

I feel like doing a bit of archeology today.

The issue described seems to have been fixed, cabal/cabal-install 2.2 give a warning about version tags and do not crash:

>cabal install
clang: warning: argument unused during compilation: '-nopie' [-Wunused-command-line-argument]
Warning: foobar.cabal:0:0: version with tags
Resolving dependencies...
Configuring foobar-0.2.0...
Building foobar-0.2.0...
Installed foobar-0.2.0

The version tag appears to be completely ignored. I suppose that is good enough or do we need to abort when encountering version tags?

[endgame]

Related: I get "version with tags" warnings if I have something that looks like a tag in the license: version (like GPL-3-or-later), even if I don't have tags in the version number.

[phadej]

Have you bumped `cabal-version` to 2.2 or 2.4 in cabal file? SPDX identifiers syppoeted only then. Before licenses are parsed roughly as package names,`GPL-3-or-later` is GPL version 3 with tags `[“or”, “later”]`. Note: valid SPDX identifier is `GPL-3.0-or-later`: 3.0, not 3.

…

Sent from my iPhone

On 2 Dec 2019, at 10.12, endgame ***@***.***> wrote: Related: I get "version with tags" warnings if I have something that looks like a tag in the license: version (like GPL-3-or-later), even if I don't have tags in the version number. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[endgame]

I had not, but that fixed my issue. Thank you.