Created attachment 215224 [details]
Patch to fix devel/readline pkg-config include path

This has been reported upstream already (see https://lists.gnu.org/archive/html/bug-readline/2019-04/msg00007.html), but a fix has not materialised yet (see https://lists.gnu.org/archive/html/bug-readline/2019-04/msg00008.html).

Readline is supposed to be used as "#include <readline/readline.h>". Currently, readline.pc includes the trailing readline/ directory component for the include path like such:

$ pkg-config --cflags readline
-I/usr/local/include/readline 

making the compiler look for /usr/local/include/readline/readline/readline.h, which is obviously wrong and no software using readline as documented wanting to use pkg-config will compile (but happens to work on Linux by accident).

The attached patch fixes the issue by stripping the final readline/ component off the include path advertised by readline.pc:

$ pkg-config --cflags readline
-I/usr/local/include