Example file tree

BUILD
docs/BUILD
docs/index.md
docs/reference/index.md

docs/BUILD

filegroup(name = "docs", srcs = glob(["**/*"]))

BUILD

pkg_files(
    name = "share_doc",
    srcs = [
        "//docs",
    ],
    strip_prefix = strip_prefix.from_pkg(),
    prefix = "usr/share/doc/foo",
)

This gives the output I expect - that the directory tree is preserved.

usr/share/doc/foo/index.md
usr/share/doc/foo/reference/
usr/share/doc/foo/reference/index.md

But.... if I do not have strip_prefix, pkg_files flattens the tree and I get the error. Error in fail: After renames, multiple sources (at least docs/index.md, docs/reference/index.md) map to the same destination. Consider adjusting strip_prefix and/or renames
This might be a carry over from legacy behavior, but it is strange and confusing.

Proposal

• pkg_files adds an attribute squash_tree bool, default=False which controls squashing the tree.
• strip prefix and any name filtering are applied first, then the results are squashed if squash_tree=False.