Wrapper name doesn't work with cmake

[froody]

I defined cmake_opt, _cmake_opt_internal = with_cfg(cmake).set("compilation_mode", "opt").build() and then declared a rule for proj like so:

package(default_visibility = ["//visibility:public"])

load("@//tools:bazel_files/opt_rules.bzl", "cmake_opt")

filegroup(
    name = "all_srcs",
    srcs = glob(["**"]),
    visibility = ["//visibility:public"],
)

cmake_opt(
    name = "proj",
    cache_entries = {
        "CMAKE_C_FLAGS": "-fPIC",
        "CMAKE_CXX_FLAGS": "-fPIC",
        "BUILD_SHARED_LIBS": "OFF",
        "BUILD_TESTING": "OFF",
        "ENABLE_TIFF": "OFF",

    },
    build_args = [ "-j64" ],
    lib_source = ":all_srcs",
    out_static_libs = ["libproj.a"],
    deps = ["@sqlite3//:sqlite3", "@curl//:curl"],
)

but that gives the following error:

ERROR: /home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/proj/BUILD.bazel:12:10: in cmake rule @@proj//:proj_/proj:
Traceback (most recent call last):
	File "/home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/rules_foreign_cc/foreign_cc/cmake.bzl", line 190, column 33, in _cmake_impl
		return cc_external_rule_impl(ctx, attrs)
	File "/home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/rules_foreign_cc/foreign_cc/private/framework.bzl", line 392, column 30, in cc_external_rule_impl
		outputs = _define_outputs(ctx, attrs, lib_name)
	File "/home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/rules_foreign_cc/foreign_cc/private/framework.bzl", line 738, column 21, in _define_outputs
		_check_file_name(lib_name)
	File "/home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/rules_foreign_cc/foreign_cc/private/framework.bzl", line 710, column 17, in _check_file_name
		fail("Symbol '%s' is forbidden in library name '%s'." % (letter, var))
Error in fail: Symbol '/' is forbidden in library name 'proj_/proj'.
ERROR: /home/tbirch/.cache/bazel/_bazel_tbirch/5dac0c5eac9fcd76e48829b4e488238f/external/proj/BUILD.bazel:12:10: Analysis of target '@@proj//:proj_/proj' failed

If I apply this diff to with_cfg.bzl, then everything builds fine:

diff --git a/with_cfg/private/wrapper.bzl b/with_cfg/private/wrapper.bzl
index 73fa461..c62cb05 100644
--- a/with_cfg/private/wrapper.bzl
+++ b/with_cfg/private/wrapper.bzl
@@ -66,7 +66,7 @@ def _wrapper(
         original_settings_label,
         attrs_to_reset):
     dirname, separator, basename = name.rpartition("/")
-    original_name = "{dirname}{separator}{basename}_/{basename}".format(
+    original_name = "{dirname}{separator}{basename}_{basename}".format(
         dirname = dirname,
         separator = separator,
         basename = basename,

[fmeum]

That workaround is probably fine for your use case, but it would break other rules: with_cfg uses a subdirectory to have the original target use the same basename as the transitioned target, which can play a role for e.g. shared library names.

Since rules should generally support subdirs in name, the best solution would be to fix this in rules_foreign_cc. I will see whether I can send a PR.

[fmeum]

As a direct workaround, try setting the lib_name attribute explicitly.