Re: Enabling builddir != srcdir by default in jhbuild

[Michael Catanzaro <mcatanzaro gnome org>]

On Sun, 2016-02-28 at 14:33 +0000, Emmanuele Bassi wrote:
> My proposal is to enable this behaviour in the default jhbuildrc, so
> that all GNOME projects automatically build in a separate root. This
> change should have no, or minimal impact on the subset of the
> moduleset that is covered by Continuous; it may require fixing the
> build of various modules in the gnome-apps or gnome-world modulesets.
> The major upsides would be that:

+1, I've been wanting to do this for a while.

There is a problem though, in that Automake's vala support is pretty
broken for git builds where builddir != srcdir, hence all (well,
virtually all) vala projects only support builddir != srcdir when
building from tarballs. Sometimes the only way to fix builddir !=
srcdir issues is to introduce broken nonsensical changes to the
Automake file [1]. So when you make this change, you should do a clean
build of all the modules and add exceptions for all the modules that
break, with the expectation that most Vala modules will be broken. (You
were probably planning to do this anyway, so just pointing it out.)

If anyone is interested in fixing this in Automake, that would be
ideal.

[1] https://bugzilla.gnome.org/show_bug.cgi?id=760679