https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91879
--- Comment #3 from Stas Sergeev <stsp at users dot sourceforge.net> ---
(In reply to Harald van Dijk from comment #1)
> archive from the DESTDIR directory and extracting it elsewhere. It is not
> supposed to be used at configure time to pick up other software, only at
> install time to determine the location to install into.
Yes, I understand that.
And yet what I see is that when gcc is building its libs,
it looks for the system headers under prefix, not under destdir.
But you are right, I probably should try mail list for
the help with that.
(In reply to Jonathan Wakely from comment #2)
> (In reply to Stas Sergeev from comment #0)
> > Hello.
> >
> > I tried to build gcc with non-empty DESTDIR.
>
> What exact commands did you run?
I have the script that runs basically "make all-gcc" and
"make" after setting some env vars. And what fails is the
plain "make" step. I can show you how exactly:
---
libtool: compile:
/home/stas/src/build-gcc/build/djcross-gcc-9.2.0/djcross/./gcc/xgcc
-B/home/stas/src/build-gcc/build/djcross-gcc-9.2.0/djcross/./gcc/
-B/usr/local/cross/i586-pc-msdosdjgpp/bin/
-B/usr/local/cross/i586-pc-msdosdjgpp/lib/ -isystem
/usr/local/cross/i586-pc-msdosdjgpp/include -isystem
/usr/local/cross/i586-pc-msdosdjgpp/sys-include -DHAVE_CONFIG_H -I.
-I../../../gnu/gcc-9.2.0/libquadmath -I
../../../gnu/gcc-9.2.0/libquadmath/../include -g -O2 -MT math/x2y2m1q.lo -MD
-MP -MF math/.deps/x2y2m1q.Tpo -c
../../../gnu/gcc-9.2.0/libquadmath/math/x2y2m1q.c -o math/x2y2m1q.o
In file included from ../../../gnu/gcc-9.2.0/libquadmath/math/x2y2m1q.c:19:
../../../gnu/gcc-9.2.0/libquadmath/quadmath-imp.h:24:10: fatal error: errno.h:
No such file or directory
24 | #include <errno.h>
| ^~~~~~~~~
compilation terminated.
---
> I don't see why DESTDIR should matter until the 'make install' step.
Please note the
-isystem /usr/local/cross/i586-pc-msdosdjgpp/include -isystem
/usr/local/cross/i586-pc-msdosdjgpp/sys-include
above. Clearly it misses the DESTDIR, and feeding the
DESTDIR there makes the problem to go away.
