Unable to build outside of source directory

[paulmenzel]

Trying to do an out of source tree build, that means, creating a separate directory and calling configure from there, fails:

[…]
[BEE] changing to build directory: /scratch/local/bee-indicopr/mod/mod_wsgi-4.9.2-20220625/build
[BEE] => entering bee_configure() ..
[BEE] /scratch/local/bee-indicopr/mod/mod_wsgi-4.9.2-20220625/source/configure --prefix=/project/indico/20220625 --bindir=/project/indico/20220625/bin --sbindir=/project/indico/20220625/sbin --libexecdir=/project/indico/20220625/libexec --sysconfdir=/project/indico/20220625/etc --sharedstatedir=/project/indico/20220625/var --localstatedir=/project/indico/20220625/var --libdir=/project/indico/20220625/lib --includedir=/project/indico/20220625/include --datarootdir=/project/indico/20220625/share --datadir=/project/indico/20220625/share --infodir=/project/indico/20220625/share/info --localedir=/project/indico/20220625/share/locale --mandir=/project/indico/20220625/share/man --docdir=/project/indico/20220625/share/doc/mod --exec-prefix=/project/indico/20220625
checking for apxs2... no
checking for apxs... /project/indico/20220625/bin/apxs
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for prctl... yes
checking Apache version... 2.4.54
checking for python... /usr/bin/python
configure: creating ./config.status
config.status: creating Makefile
[BEE] <= leaving bee_configure() ..
[BEE] => entering bee_build() ..
[BEE] make -j32
make: *** No rule to make target 'src/server/mod_wsgi.c', needed by 'src/server/mod_wsgi.la'.  Stop.

[GrahamDumpleton]

Out of tree builds have never been possible. It isn't just structuring the Makefile correctly, with part of the issue being the apxs command from Apache which does the actual build. Others have raised the same issue in the past but no one has provided a solution for getting it working. If you have suggestions of how to make it work then I can look at it.