bootstrap/8657: No rule to make target `bootstrap' in directory 'gcc'

[Zack Weinberg]

Neil Booth <neil@daikokuya.co.uk> writes:

>>     
>>     First, we highly recommend that GCC be built into a separate
>>     directory than the sources which does not reside within the
>>     source tree. This is how we generally build GCC; building where
>>     srcdir == objdir should still work, but doesn't get extensive
>>     testing; building where objdir is a subdirectory of srcdir is
>>     unsupported.
>
> This latter "unsupported" configuration is what (at least) me and
> Jakub build on, and it has *always* worked.  Maybe the docs should
> be updated.

In my experience, if objdir is a subdirectory of srcdir AND configure
is invoked by a relative pathname, it doesn't work.  But if configure
is invoked by an absolute pathname, objdir can happily be a
subdirectory of srcdir; and if objdir is not a subdirectory of srcdir,
relative paths work fine.

I don't remember the exact failure mode, but it was clearly a case of
some shell script fragment somewhere getting mixed up about how many
../ components it needed to put in a pathname.

zw