I released version 29.1.1.0 of Compat, the Elisp compatibility library.

This release comes with improvements to the inner workings of Compat and
better test coverage. Compat ensures that only necessary definitions are
byte compiled. No unnecessary files are loaded, e.g., on Emacs 28 only
compat-29 is loaded, while on Emacs 29 and newer none of the
compatibility libraries is loaded. As a consequence, Compat does not add
any cost to a running Emacs process if you use Emacs 29 or newer.

On the bug fix side, this release removes the `string-pixel-width'
function, since performance turned out to be insufficient for some
popular downstream packages like doom-modeline. Furthermore the function
is already widely used by packages on MELPA (without depending on
Compat, but guarded by fboundp checks).

See the NEWS.org file for further details. Please let me know if you
have questions or improvement proposals.

Daniel