Meson detects the path of the target shell via `find_program("sh")`,
which essentially does a lookup via `PATH`. We know that almost all
systems have "/bin/sh" available though, which makes it the superior
choice as a default value.
Adapt `find_program()` to prefer "/bin/sh" over any other "sh"
executable.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
fs = import('fs')
-shell = find_program('sh')
+shell = find_program('/bin/sh', 'sh')
tclsh = find_program('tclsh')
wish = find_program('wish')