Ticket #270 (closed defect: fixed)

Opened 8 months ago

Last modified 7 months ago

Build executables that can be run "in-place"

Reported by: waern Assigned to:
Priority: normal Milestone:
Component: Cabal library Version: 1.2.3.0
Severity: normal Keywords:
Cc: Difficulty: easy (<4 hours)
GHC Version: 6.8.2 Platform:

Description

It would be nice if Cabal could build executables that could be told where to get their data files (etc), instead of always hard-wiring them to the installation dirs. Perhaps an environmental variable could be used to specify where the data files are. This would enable us to run applications "in-place", i.e. from the source directory directly, which would be useful for test suites, for example.

David

Change History

04/12/08 11:22:21 changed by duncan

  • difficulty changed from normal to easy (<4 hours).

Yes, we could have the generated Paths_<pkgname> module check an environment variable and if it exists, use that in preference to the normal value.

Doesn't sound too hard. It might also be a good opportunity to clean up that code and move it into it's own module.

05/21/08 09:09:15 changed by duncan

  • status changed from new to closed.
  • resolution set to fixed.

This is now done. However as the last patch notes it's not all that convenient yet. You'd have to invoke the program like: 

$ foo_datadir="." dist/build/foo/foo

And if the program looked at its bindir, libdir or libexecdir then those would need to be specified too. Someone could add a feature to cabal/cabal-install to launch the program or or ghci/hugs with the right env vars. 

Sun Apr 13 14:41:55 BST 2008  Johan Tibell <johan.tibell@gmail.com>
  * Made it possible to run executeables with data files in place.
  Added an environment variable, DATA_DIR, that is checked before the
  installation data directory is used.

Wed May 14 10:42:03 BST 2008  Duncan Coutts <duncan@haskell.org>
  * Prefix the datadir env var with the package name
  Partly as it is more likely not to clash with other users and since
  in general different libs within a program may need different paths.

Mon May 19 18:38:08 BST 2008  Duncan Coutts <duncan@haskell.org>
  * Allow the bindir, libdir and libexec dir to be specified via env vars too
  Same as for the datadir. Eg for package Foo, you'd use
  Foo_bindir=... Foo_datadir=... Foo_libexecdir=... ./Foo
  The next step would be generating a wrapper script that allows
  running the program inplace. It should also work for a library.