qAddDependentFile is broken with new-install

[hasufell]

minimal reproducible project https://github.com/hasufell/new-install-fail

new-install:

$ cabal new-install -j1 exe:new-install-fail
Wrote tarball sdist to
/home/maerwald/git/new-install-fail/dist-newstyle/sdist/new-install-fail-0.1.0.0.tar.gz
Resolving dependencies...
Build profile: -w ghc-8.6.2 -O1
In order, the following will be built (use -v for more details):
 - new-install-fail-0.1.0.0 (exe:new-install-fail) (requires build)
Configuring executable 'new-install-fail' for new-install-fail-0.1.0.0..
Preprocessing executable 'new-install-fail' for new-install-fail-0.1.0.0..
Building executable 'new-install-fail' for new-install-fail-0.1.0.0..
[1 of 1] Compiling Main             ( src/Main.hs, dist/build/new-install-fail/new-install-fail-tmp/Main.o )

<no location info>: error:
    resources/foo.md: openBinaryFile: does not exist (No such file or directory)
Warning: Some package(s) failed to build. Try rerunning with -j1 if you can't
see the error.

new-build:

$ cabal new-build -j1 exe:new-install-fail
Resolving dependencies...
Build profile: -w ghc-8.6.2 -O1
In order, the following will be built (use -v for more details):
 - new-install-fail-0.1.0.0 (exe:new-install-fail) (first run)
Configuring executable 'new-install-fail' for new-install-fail-0.1.0.0..
Preprocessing executable 'new-install-fail' for new-install-fail-0.1.0.0..
Building executable 'new-install-fail' for new-install-fail-0.1.0.0..
[1 of 1] Compiling Main             ( src/Main.hs, /home/maerwald/git/new-install-fail/dist-newstyle/build/x86_64-linux/ghc-8.6.2/new-install-fail-0.1.0.0/x/new-install-fail/build/new-install-fail/new-install-fail-tmp/Main.o )
Linking /home/maerwald/git/new-install-fail/dist-newstyle/build/x86_64-linux/ghc-8.6.2/new-install-fail-0.1.0.0/x/new-install-fail/build/new-install-fail/new-install-fail ...

[phadej]

You don't specify

extra-source-files:
  resources/foo.md

in new-install-fail.cabal

[hasufell]

Yeah, it seems cabal new-install switches to /tmp during build and then only includes what is the output of sdist right? While cabal new-build still works without.

[phadej]

Yes, new-install does sdist and installs that package. That way installs can be hashed.

I tag this issue as documentation, as new-install for local packages is undocumented in the manual; it should really explain what happens (and especially why).