Cabal run & install broken

[adityagupta1089]

Describe the bug
I have a project with 1 library + multiple executables. I have defined ghc-options in .cabal file such as -O2 and -fllvm. These are not being picked up by cabal run --enable-profiling or cabal install, but those are being picked up when I do just cabal run or cabal build. I checked this using -v3 flag. Also it is building all the executables even though I specififed using cabal install exe:<executable1>

To Reproduce
Steps to reproduce the behavior: mentioned above

$ cabal run executable1 # uses flags from .cabal file
$ cabal install executable1 # doesn't use flags from .cabal file and starts building all executables
$ cabal run --enable-profiling executable1 -- +RTS -p # doesn't use flags from .cabal file 

Please use version-prefixed commands (e.g. v2-build or v1-build) to avoid ambiguity.

Expected behavior
mentioned above

System information

• Operating system: Arch
• cabal, ghc versions: 3.4, 8.10.4

Additional context
NA

[fgaz]

Cannot reproduce. Could you attach / link to a minimal project that reproduces this?

Also it is building all the executables even though I specififed using cabal install exe:

What is the build-type? That's a limitation of the Custom build-type iirc

[adityagupta1089]

will attach a MWE asap

[adityagupta1089]

Hi I created a MWE project: https://github.com/adityagupta1089/cabal-test

• cabal -v3 run problem1 | grep "\-O2" working
• Install (not using cabal flags and installing all executables)

❯ cabal install problem1 --installdir=./bin --install-method=copy --overwrite-policy=always
Wrote tarball sdist to
/home/aditya/cabal-test/dist-newstyle/sdist/euler-0.1.0.0.tar.gz
Resolving dependencies...
Build profile: -w ghc-8.10.4 -O1
In order, the following will be built (use -v for more details):
 - euler-0.1.0.0 (lib) (requires build)
 - euler-0.1.0.0 (exe:problem3) (requires build)
 - euler-0.1.0.0 (exe:problem2) (requires build)
 - euler-0.1.0.0 (exe:problem1) (requires build)
Starting     euler-0.1.0.0 (lib)
Building     euler-0.1.0.0 (lib)
Installing   euler-0.1.0.0 (lib)
Completed    euler-0.1.0.0 (lib)
Starting     euler-0.1.0.0 (exe:problem3)
Starting     euler-0.1.0.0 (exe:problem2)
Starting     euler-0.1.0.0 (exe:problem1)
Building     euler-0.1.0.0 (exe:problem3)
Building     euler-0.1.0.0 (exe:problem2)
Building     euler-0.1.0.0 (exe:problem1)

• Running with profiling: (not using cabal flags)

❯ cabal run --enable-profiling problem1 -- +RTS -p
Build profile: -w ghc-8.10.4 -O1
In order, the following will be built (use -v for more details):
 - euler-0.1.0.0 (lib)  --enable-profiling (configuration changed)
 - euler-0.1.0.0 (exe:problem1)  --enable-profiling (configuration changed)
Configuring library for euler-0.1.0.0..
Preprocessing library for euler-0.1.0.0..
Building library for euler-0.1.0.0..

Also I get this weird warning while running/building, etc.

Warning: The package has an extraneous version range for a dependency on an
internal library: euler >=0 && ==0.1.0.0, euler >=0 && ==0.1.0.0, euler >=0 &&
==0.1.0.0. This version range includes the current package but isn't needed as
the current package's library will always be used.

[fgaz]

The warning is #5119

[adityagupta1089]

@fgaz any idea about the other bugs? any workarounds?

[fgaz]

Still cannot reproduce. I see the ghc options in the output of all three commands when running with -v3.

I see you're on arch, perhaps something in your ~/.cabal/config is interfering?

[fgaz]

Ah wait, maybe you're referring to the "Build profile: -w ghc-8.8.4 -O1" output? The meaning of that is that optimizations are set at 1 at the project level, but you're still overriding to 2 at the component (executable) level. It agree it's a bit confusing (#6221)

[adityagupta1089]

@fgaz Thanks. Seems like then the problem with flags is spurious. Only difficulty I am facing are then:

• Can't install only a single binary (it installs all of them)
• Maintaining a project with 100-200s of executables (writing executable blocks for all of them, I've tried a generation script)

So I'm currently using a makefile to glob the executable source files (Problem{1,2,3} in the MWE) and build using stack ghc (I wanted to use ghc but required some dependencies too)
But this method suffers from the problem when I need to profile a single binary (and I need profiling libraries), it's difficult if I haven't defined an executable (in which case both cabal & stack do this for me). and defining 100-200s of executables in .cabal or .yaml (hpack) are troublesome.

Can you give some advice how to structure or which build-tools to use for my project?

[fgaz]

Can't install only a single binary (it installs all of them)

weird, I thought that was fixed. I'll have to check.
If that's the case you can still hack around it with build, run, and list-bin (all of them are granular enough)

Maintaining a project with 100-200s of executables (writing executable blocks for all of them, I've tried a generation script)

Common stanzas should make this less verbose, but you still have to at least enumerate the executables. Obtaining a list of exes from the file system will not be possible (cabal files are required to be self-contained in that sense). So generating the file looks like the best solution.

I wanted to use ghc but required some dependencies too

There are some ways to do that with cabal too. Either:

• use --write-ghc-environment-files=always or set write-ghc-environment-files to always in your ~/.cabal/config, and then build the package. ghc will pick up the generated .ghc.environment file. Or...
• use cabal exec ghc. Or...
• use the cabal-env prototype mentioned in Separate cabal install --lib into own command (cabal env) #6481 to generate an environment file (this solution does not even need a .cabal file)

[adityagupta1089]

@fgaz Thanks for the suggestions, I ran into cabal hell so using stack exec ghc for now with a makefile to build binaries. Also stack ghc -profile also works for me when I need to profile. make -j<num> is really fast compared to cabal or stack.