Re: [libvirt] [PATCH] tests: guarantee abs_srcdir in all C tests

While trying to debug a failure of virpcitest during 'make distcheck', I noticed that with a VPATH build, 'cd tests; ./virpcitest' fails for an entirely different reason. To reproduce the distcheck failure, I had to run 'cd tests; abs_srcdir=/path/to/src ./virpcitest'. But we document in HACKING that all of our tests are supposed to be runnable without requiring extra environment variables. The solution: hardcode the location of srcdir into the just-built binaries, rather than requiring make to prepopulate environment variables. With this, './virpcitest' passes even in a VPATH build (provided that $(srcdir) is writable; a followup patch will fix the conditions required by 'make distcheck').