both 4.19.90 from official kernel tarball and 4.19.88 from the
sabotage-linux headers-only package are added. the latter should be
preferred unless you have a reason not to, as it's much smaller and
has some patches that improve interaction with musl.
support for all earlier kernel header versions will be dropped soon,
since everything prior to 4.16 has incompatibilities with 32-bit archs
moving to time64.
Rich Felker