Bug#876901: karchive FTBFS: test failures

[Lisandro Damián Nicanor Pérez Meyer <perezmeyer@gmail.com>]

mattia@warren /tmp/tmp % cat test.c
#include <stdio.h>
int main() {
    printf("%s\n", __FILE__);
}

mattia@warren /tmp/tmp % gcc test.c ; ./a.out
test.c
mattia@warren /tmp/tmp % gcc ./test.c ; ./a.out
./test.c
mattia@warren /tmp/tmp % gcc /tmp/tmp/./test.c ; ./a.out
/tmp/tmp/./test.c


So Qt *depends* on gcc+the toolchain using __FILE__ with the full
path. I consider this valid usage because it is somehow always
enforced within Qt, so packages using this macro and dpkg >= 1.20.7.1
should consider adding something like:

# Disable fixfilepath feature, as it triggers build failures when
# enabled.
export DEB_BUILD_MAINT_OPTIONS = hardening=+all reproducible=-fixfilepath

At very least until we can find a fix for this, if possible.