Lift the basename/libgen.h shenanigans back out of portability.c and make it a static inline in portability.h, and prototype dirname() while we're at it.
diff --git a/lib/portability.h b/lib/portability.h
index bb1f5ae..143d10f 100644
--- a/lib/portability.h
+++ b/lib/portability.h
@@ -66,8 +66,12 @@
// the table entry for the basename command. They didn't make a new function
// with a different name for their new behavior because gnu.
//
-// Implement our own in portability.c and don't use their broken header.
-char *basename(char *path);
+// Solution: don't use their broken header, provide an inline to redirect the
+// correct name to the broken name.
+
+char *dirname(char *path);
+char *__xpg_basename (char *path);
+static inline char *basename(char *path) { return __xpg_basename(path); }
// uClibc pretends to be glibc and copied a lot of its bugs, but has a few more
#if defined(__UCLIBC__)
@@ -137,9 +141,9 @@
#ifndef MNT_DETACH
#define MNT_DETACH 2
#endif
-#endif
+#endif // Old glibc
-#endif
+#endif // glibc in general
#ifndef __GLIBC__
// POSIX basename.