lix/doc/manual/rl-next/rename-lixexpr.md

synopsis	credits	category
Rename all the libraries nixexpr, nixstore, etc to lixexpr, lixstore, etc	jade	Breaking Changes

The Lix C++ API libraries have had the following changes:

• Includes moved from include/nix/ to include/lix/
• pkg-config files renamed from nix-expr to lix-expr and so on.
• Libraries renamed from libnixexpr.so to liblixexpr.so and so on.

There are other changes between Nix 2.18 and Lix, since these APIs are not stable. However, this change in particular is a deliberate compatibility break to force downstreams linking to Lix to specifically handle Lix and avoid Lix accidentally getting ensnared in compatibility code for newer CppNix.

Migration path:

• expr.hh -> lix/libexpr/expr.hh
• nix/config.h -> lix/config.h

To apply this migration automatically, remove all <nix/> from includes, so #include <nix/expr.hh> -> #include <expr.hh>. Then, the correct paths will be resolved from the tangled mess, and the clang-tidy automated fix will work.

Then run the following for out of tree projects (header filter is set to only fix instances in headers in ../src relative to the compiler's working directory, as would be the case in nix-eval-jobs or other things built with meson, e.g.):

lix_root=$HOME/lix
(cd $lix_root/clang-tidy && nix develop -c 'meson setup build && ninja -C build')
run-clang-tidy -checks='-*,lix-fixincludes' -load=$lix_root/clang-tidy/build/liblix-clang-tidy.so -p build/ -header-filter '\.\./src/.*\.h' -fix src