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Cade's Dotfiles

Clang cannot load `libz3` during an in-progress upgrade

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Source: Troubleshooting reference

Symptom: a formula failure ends with a separate loader error such as:

clang: error while loading shared libraries: libz3.so.4.15: cannot open shared object file

Root cause: Bundle upgraded Z3 before unversioned LLVM. The installed LLVM still needs Z3’s previous major SONAME, while opt/z3 already selects the new keg. This is independent of a formula that was compiled with GCC and usually repairs itself when the same Bundle run reaches LLVM.

The Linux installer reconciles this pair before Bundle: it upgrades an outdated LLVM in upgrade mode, reinstalls a current keg whose linkage is broken, and checks both brew linkage and the unversioned Clang executable again after Bundle.

Do not point the old SONAME at the new major library or repoint opt/z3 during the active transaction. After all Homebrew processes exit, rerun ~/dotfiles/bootstrap.sh upgrade. For a manual check, run:

Terminal window
"$(brew --prefix)/bin/clang" --version

If it still reports the old Z3 SONAME, upgrade an outdated LLVM or reinstall a current but broken keg, then verify its linkage:

Terminal window
if [[ -n "$(brew outdated --formula llvm)" ]]; then
    brew upgrade llvm
else
    brew reinstall llvm
fi
brew linkage --test llvm
"$(brew --prefix)/bin/clang" --version