This can be fixed be creating a symlink :
ln -s /usr/local/stow/skarnet/lib/s6/libs6.a
No, this is intentional. The skarnet.org build system installs static
libraries in a subdirectory of $prefix/lib by default, as shown in the
output of ./configure --help.
If you want to link against them, you need to give appropriate
options to ./configure. So, in your case:
For execline, you'd add
For s6, you'd add
And for s6-rc, you'd add
That's impractical, but a clear separation of build-time files and
run-time files is worth the small inconvenience.
Alternatively, if you don't care about this separation and simply want
everything in /usr/local/stow/skarnet/lib, you can say so at
time, by giving the following option to every ./configure in the stack:
which will achieve what you're looking for.