Currently Zig cache is in /tmp/zig-cc. It could be moved to a Bazel workspace by creating a new Bazel repository, in a similar way how bazel-gazelle does things, as suggested by @linzhp:

https://github.com/bazelbuild/bazel-gazelle/blob/3a1235c298b7dc11fa7ba994db4f92587c1aca79/internal/go_repository.bzl#L126

Discussion in #zig on Bazel slack: https://bazelbuild.slack.com/archives/C04N6NE1GRM/p1685200818998739?thread_ts=1684869528.116339&cid=C04N6NE1GRM