Trying to build from current git master HEAD seems to be broken. Have tried
various recipes (make, make bootstrap, make extraclean make bootstrap etc).
Had no issues building a couple of days ago. Build fails with the following
error

Loading bindings (source)...
make -C ../lisp compile-first EMACS="../src/bootstrap-emacs"
make[3]: Entering directory '/home/tim/git/emacs/lisp'
  ELC      emacs-lisp/macroexp.elc
desired fingerprint:
85f312322694a812c6415eae9aea6afbbc20b2924e0617f410218006e1fc48c8
found fingerprint:
2db1c43551c18cfe037e9db53b353bb37add978d1134069ed31ee14138e7d2fc
emacs: could not load dump file
"/usr/local/libexec/emacs/28.0.50/x86_64-pc-linux-gnu/emacs.pdmp": not
built for this Emacs executable
make[3]: *** [Makefile:309: emacs-lisp/macroexp.elc] Error 1
make[3]: Leaving directory '/home/tim/git/emacs/lisp'
make[2]: *** [Makefile:850: bootstrap-emacs.pdmp] Error 2
make[2]: Leaving directory '/home/tim/git/emacs/src'
make[1]: *** [Makefile:449: src] Error 2
make[1]: Leaving directory '/home/tim/git/emacs'
make: *** [Makefile:1147: bootstrap] Error 2

This is on Ubuntu 21.04.