haskell-process-cabal-build doesn't build under certain conditions

[psibi]

In haskell-mode, when I do cabal build using haskell-process-cabal-build, I get this:

Complete: cabal build (0 compiler messages)

But in the haskell-process-log, I see this:

-> ":!cd /home/sibi/snapshot-analysis/ && cabal build
"
<- "/bin/sh: 1: cabal: not found

I don't get how it's not able to see my cabal path. In fact, I have these things in my emacs configuration, just to be sure:

(setq exec-path (cons "~/.cabal/bin" exec-path))

(setenv "PATH"
  (concat
   "~/.cabal/bin/" ":"
   (getenv "PATH")
  )
)

The cabal which I have is inside ~/.cabal/bin. Let me know if you need any other details.

[psibi]

Everything works fine, if I switch over to terminal and run the usual cabal build command.

[chrisdone]

This is an FAQ. Let me find the link.

[chrisdone]

https://github.com/haskell/haskell-mode/wiki/PATH

[psibi]

@chrisdone As already mentioned in the original thread, I have set the PATH as stated in the FAQ. The cabal initially works within the mode but after some time, it doesn't.

[psibi]

Just to add extra information, I have set the process-type as cabal-repl.

When I do the C-c-l from the haskell source code, it works. When I do C-c-c from the cabal file, it gives out the above error that it's not able to find cabal.

[chrisdone]

Does M-! cabal work? Also try in the REPL typing :!echo $PATH to see what's up.

[psibi]

λ> :!echo $PATH
~/.cabal/bin/:/home/sibi/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:.cabal-sandbox/bin/

I'm not sure what do you mean by M-! cabal. If you meant this: M-x cabal, then I'm not able to find any elisp function named cabal in my environment. In fact, If I run cabal build in M-x compile, emacs recognizes the cabal path and executes it.

[chrisdone]

I meant M-! cabal. I.e. type the keys M-! then type cabal then type RET.

[tobiasgwaaler]

M-! is usually bound to shell-command, so it would try to run cabal from a shell

[psibi]

M-! produces this:

cabal: no command given (try --help)

[ivan-m]

Try using $HOME instead of ~ for your PATH (actually, you'll probably need to use getenv to get the HOME variable); my guess is that it's a problem with shell expansion.

[psibi]

@ivan-m Tried both $HOME and the exact path, but that doesn't seem to solve the problem.

[chrisdone]

Very strange. Oh! Do M-! which cabal. Perhaps cabal is coming from somewhere else?

[psibi]

Ok, it starts working after I put the complete path like this: /home/user/.cabal/bin

[psibi]

M-! which cabal throws error message:

(Shell command failed with code 1 and no output) [2 times]

On bash, it gives:

/home/sibi/.cabal/bin//cabal

The doule // I think is not good and I have no clue how that got setup.

[psibi]

@chrisdone Shall I close the issue ?

And maybe we can update the FAQ to try this in case everything else fails.

[ivan-m]

The // shouldn't matter.

Can you do (for example) M-! which emacs just to make sure that's working?

[chrisdone]

Maybe be a fix: #282 But the PATH stuff is still a worry.

[psibi]

@ivan-m Restarted the emacs and tried it again to receive the same error:

(Shell command failed with code 1 and no output)

Just curious why // doesn't matter ?

[ivan-m]

Well, I've never seen // make a difference in a path in bash at least.

But that error makes it look like the problem might be with your emacs or emacs config. Can you try it with emacs -Q?

[psibi]

@ivan-m Thanks, will try this and report that once I go to my office again. (~ after 2 days).

[psibi]

@ivan-m Now it gives proper path when I use M-! (when started with and without -Q in emacs).

[gracjan]

@psibi: Is this PATH issue working for you?

[gracjan]

Do not hessitate to write a note here if this PATH issue is still bothering you.