Strange `stack setup` behaviour when `DESTDIR` is set

[ehamberg]

Calling stack setup, with DESTDIR set fails since it will end up being installed in $DESTDIR$HOME/.stack/programs/x86_64-linux/ghc-7.10.2/. This happened on a CI server that called make DESTDIR=$BUILD_DIR install and relied on the fact that the install target was calling other targets that eventually called stack setup.

Here's what happens on Debian 8.2 for a user with HOME=/var/lib/buildkite-agent:

$ rm -rf ~/.stack/
$ DESTDIR=/tmp/test stack setup
Downloaded lts-3.16 build plan.
Caching build plan
Fetched package index.
Populated index cache.
Preparing to install GHC to an isolated location.
This will not interfere with any system-level installation.
Downloaded ghc-7.10.2.
Installed GHC.
Executable named ghc not found on path: ["/var/lib/buildkite-agent/.stack/programs/x86_64-linux/ghc-7.10.2/bin","/usr/local/bin","/usr/bin","/bin","/usr/local/games","/usr/games"]
$ ls var/lib/buildkite-agent/.stack/programs/x86_64-linux/ghc-7.10.2/
bin  lib  share

Note that the install ends up in $DESTDIR$HOME which here is /tmp/test/var/lib/buildkite-agent.

(This was solved by changing the build to be make && make DESTDIR=$BUILD_DIR install so that DESTDIR is only set for the install target.)

[ehamberg]

To clarify: Even if stack setup is meant to honour DESTDIR (is it?), it looks like the files end up being installed into $DESTDIR$HOME, which to me looks like it's definitely a bug.

[mgsloan]

I don't think stack setup is meant to honour DESTDIR, that's part of the ghc makefile. I think we should filter this from the environment when installing GHC, and possibly other env vars.

So in your particular case, during build, other makefiles get invoked which use DESTDIR? Or does cabal-install use DESTDIR (doesn't afaict).

[ehamberg]

So in your particular case, during build, other makefiles get invoked which use DESTDIR? Or does cabal-install use DESTDIR (doesn't afaict).

We specified DESTDIR ourselves when calling make from our build server. On a fresh server, where stack setup was called, this would lead to it being set for that invocation, making stack setup fail.

[borsboom]

Sounds like we should just remove DESTDIR from the environment when installing GHC.

[mgsloan]

That sounds like a good resolution to me! It should warn about unsetting the env var, incase the user is doing it intentionally.

[mgsloan]

Fixed! Feel free to re-open if not.