FONT_S=${FONT_S:-${S}} ${S} is available only in src_*. I guess you can just use ${WORKDIR}/${P} instead.
Note that his may actually become legal because the scope of breakage is huge.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=58cea2803d7aa7b1a98f72aa55b6221618dc5e5f commit 58cea2803d7aa7b1a98f72aa55b6221618dc5e5f Author: Ulrich Müller <ulm@gentoo.org> AuthorDate: 2020-02-14 14:50:18 +0000 Commit: Ulrich Müller <ulm@gentoo.org> CommitDate: 2020-03-20 15:40:25 +0000 font.eclass: Don't assign FONT_S in global scope, allow an array. Accessing ${S} in global scope is not allowed by PMS, therefore remove the global variable assignment of FONT_S which uses it. Add a fallback to ${S} in font_src_install() instead. Allow FONT_S to be an array, if there are multiple directories. Support for whitespace-separated lists will be kept for some time, and a QA warning will be shown. Die if pushd or popd fails. Closes: https://bugs.gentoo.org/613108 Closes: https://bugs.gentoo.org/709578 Signed-off-by: Ulrich Müller <ulm@gentoo.org> eclass/font.eclass | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-)