what is the life time of symlinks in <execution_root>/external/ ?

[jens-elmenthaler]

I'm running clangd for C++ source code that is built with bazel. I can extract the compile commands via some bazel query and in general it works nicely.

However, we use some external repos as well and their header files seem to be passed to the c++ compiler via symlinks in <execution_root>/external/. After a complete build of the bazel workspace (bazel build //...) all the header files are accessible as specified in the compiler's command line. I can also selectively recompile single targets and nothing vanishes.
But as soon as I execute bazelisk query 'kind("generated file", //...:all-targets)' and rebuild a single target afterwards, many symlinks from <execution_root>/external are missing and letting clangd reindex the code base will mostly fail.

My question now: is this an intended use model at all? How long will the symlinks in <execution_root>/external be valid? Should a bazel query already invalidate them?