Why does bazel's rules_foreign_cc make not find/create the artifacts? - gnu-make

Question

I want to create a make rule from rules_foreign_cc.
But even the minimal example below is causing issues for me.
With the following setup:
.
├── BUILD (empty)
├── hello
│   ├── BUILD.bazel
│   ├── hello.c
│   ├── Makefile
│   └── WORKSPACE (empty)
└── WORKSPACE
WORKSPACE:
workspace(name = "test")
load("#bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
name = "rules_foreign_cc",
sha256 = "2a4d07cd64b0719b39a7c12218a3e507672b82a97b98c6a89d38565894cf7c51",
strip_prefix = "rules_foreign_cc-0.9.0",
url = "https://github.com/bazelbuild/rules_foreign_cc/archive/refs/tags/0.9.0.tar.gz",
)
load("#rules_foreign_cc//foreign_cc:repositories.bzl", "rules_foreign_cc_dependencies")
# This sets up some common toolchains for building targets. For more details, please see
# https://bazelbuild.github.io/rules_foreign_cc/0.9.0/flatten.html#rules_foreign_cc_dependencies
rules_foreign_cc_dependencies()
local_repository(
name = "hello",
path = "hello",
)
hello/BUILD.bazel:
load("#rules_foreign_cc//foreign_cc:defs.bzl", "make")
filegroup(
name = "hellosrc",
srcs = glob([
"**",
]),
)
make(
name="hello_build",
lib_source=":hellosrc",
out_bin_dir="",
out_binaries=["hello_binary"],
targets=["all"],
)
hello/Makefile:
all:
gcc hello.c -o hello_binary
clean:
rm hello
hello/hello.c:
#include <stdio.h>
int main () {
printf("hello\n");
return 0;
}
and running
bazel build #hello//:hello_build
I'm getting
INFO: Analyzed target #hello//:hello_build (43 packages loaded, 812 targets configured).
INFO: Found 1 target...
ERROR: /home/timotheus/.cache/bazel/_bazel_timotheus/a791a0a19ff4a5d2730aa0c8954985c4/external/hello/BUILD.bazel:10:5: output 'external/hello/hello_build/hello_binary' was not created
ERROR: /home/timotheus/.cache/bazel/_bazel_timotheus/a791a0a19ff4a5d2730aa0c8954985c4/external/hello/BUILD.bazel:10:5: Foreign Cc - Make: Building hello_build failed: not all outputs were created or valid
Target #hello//:hello_build failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 12.426s, Critical Path: 12.22s
INFO: 7 processes: 5 internal, 2 linux-sandbox.
FAILED: Build did NOT complete successfully
Basically, I have no idea where Bazel is looking for the created binaries (are they even created?). I tried to set out_bin_dir to different values or not set it at all, all with the same effect.
I expect Bazel to generate the binary and find it - or at least give me a hint what it does.

Answer 1

And I think I found the solution.
make of rules_foreign_cc expects that the make project has an install target.
If that's not the case, it doesn't find the binaries.
This is how I could fix my minimal example - adding an install target to the Makefile
install:
cp -rpv hello_binary $(PREFIX)