glibc's fts(3) is broken

Discovered this while testing quark on musl: https://wiki.musl-libc.org/faq#Q:-Why-is-%3Ccode%3Efts.h%3C/code%3E-not-included?

It makes sense for us to include our own fts, chimera-linux has a port, or just include the one from openbsd verbatim.

glibc is the gift that keeps on giving.

Start with the linked musl-libc FAQ to understand why fts.h is unavailable, then compare the Chimera Linux port with the OpenBSD implementation mentioned in the issue. Determine which approach fits quark and verify that the resulting fts support addresses musl-based builds; no repository file or test is named.

Written by the indexing model from the issue text.