Try 1 at specification:
Fedora is based on GNU tools versus strict POSIX compliant ones. As
such, packagers can expect that /bin/sh is /bin/bash, /bin/awk is
/bin/gawk, /bin/cc is /bin/gcc ad naseum. This means that unless
specified elsewhere that a 'bashism', 'gawkism', 'gcc-ism' is not
to
be used, packagers may rely on tools to act as the upstream GNU tools
in their spec files.
This is the kind of spec that leads to spoiled upstreams putting
/bin/sh in shebangs and scratching their heads when they get bug
reports for stricter systems...
I'd be happier if Fedora was not part of the problem and maintainers
were encouraged to figure out the correct shebang (and when in doubt
use /usr/bin/bash). And since RPM appears to be configurable for the
default interpreter, have it use /usr/bin/bash by default.
Dridi