The "Render PKGBUILD" step's Python heredoc built its old_source match
string via an f-string, escaping literal braces as `${{pkgver}}` — which
put that exact four-character sequence directly in this workflow file's
own YAML text. Gitea Actions scans a run: block for `${{ ... }}` and tries
to evaluate whatever's inside as one of its own expressions before the
shell ever sees the script; "pkgver" isn't a valid expression context, so
every run has been failing that interpolation and emptying the step
instead of raising anything visible there. The next step's `makepkg` then
failed with "PKGBUILD does not exist" — the actual point of failure was
one step earlier and unrelated to AUR credentials.
Rebuilt the same match string with a "$" variable and plain concatenation
so the file's own text never contains the trigger sequence. Verified by
extracting the exact heredoc and running it standalone against the real
PKGBUILD template — renders identically to the intended output.