This command works with Qt 6.5.6/6.7.0 but fails with Qt 6.7.2:

rcc -compress-algo zstd resources.qrc

Error:

/home/USER/Qt/6.7.2/gcc_64/libexec/rcc: Zstandard support not compiled in

Consequences
Suppose that a library contains zstd-compressed resources. It is built with Qt 6.5.6 LTS and released to the public.

An app built with Qt 6.7.2 cannot link to that library, unless the user builds Qt 6.7.2 from source to enable zstd:

/usr/bin/ld: /usr/lib/libMyLib.so: undefined reference to `qt_resourceFeatureZstd@Qt_6'

Notes
Qt 6.8.0-beta2 seems to be fine. I'd like to double-check that Qt 6.7.3 will contain the fix too.