Building cabal-helper-0.8.1.2 with Stack failed with 'Dependency cycle detected' error. It seems to be https://github.com/commercialhaskell/stack/issues/4265 Stack bug. As a temporary solution I added source code of cabal-helper package to vendor directory and commented out 'build-tool-depends: cabal-helper:cabal-helper-wrapper' line in the cabal-helper.cabal file.
1.8 KiB
cabal-helper
Cabal's little helper provides access to build information gathered by cabal
when configuring a project. Specifically we're interested in retrieving enough
information to bring up a compiler session, using the GHC API, which is similar
to running cabal repl
in a project.
While simple in principle this is complicated by the fact that the information Cabal writes to disk is in an unstable format and only really accessible through the Cabal API itself.
Since we do not want to bind the user of a development tool which utilises this library to a specific version of Cabal we compile the code which interfaces with the Cabal library's API on the user's machine, at runtime, against whichever version of Cabal was used to write the on disk information for a given project.
If this version of Cabal is not available on the users machine anymore, which is
fairly likely since cabal-install is usually linked statically, we have support
for compiling the Cabal library also. In this case the library is installed into
a private, isolated, package database in $XDG_CACHE_HOME/cabal-helper
so as to
not interfere with the user's package database.
IRC
If you have any problems, suggestions, comments swing by #ghc-mod (web client) on Freenode. If you're reporting a bug please also create an issue here so we have a way to contact you if you don't have time to stay.
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