Re: [PATCH v2] configure: add support for pseudo-"in source tree" builds

[Paolo Bonzini <pbonzini@redhat.com>]

On 21/08/20 12:54, Kevin Wolf wrote:
>>> Sounds like it will be painful to switch between branches based on make
>>> and branches based on meson. By extension, it will also be painful to
>>> check out and build old versions for comparison, or doing that even more
>>> than once during git bisect. :-(
>> Not if you switch to out-of-tree builds...
> I don't see what out-of-tree builds change about this unless I delete
> and reconfigure them after each step? Even in those cases where I use
> out-of-tree builds, I often reuse the same directory.

In two ways:

1) bisection will rarely jump around the point where Meson was
introduced.  First, because if it coincides with the 5.1.0 release, then
you know in advance if the problem was introduced before or after the
merge.  Second, because the bisection will quickly land on a merge
commit, and then you can (just for going down the merged branch) use a
separate out-of-tree build directory.

2) for the rare case of working on a branch that was developed pre-Meson
and has not been rebased (or need not be rebased), you again use a
separate out-of-tree build directory just for that one, and you don't
have to worry about doing distclean or an incremental builds.

Paolo