coreos-devel/fero-client: fix grpc-sys-0.2.3 + glibc-2.32 compile issue

Signed-off-by: Thilo Fromm <thilo@kinvolk.io>

sdk_container/src/third_party/coreos-overlay/coreos-devel/fero-client/fero-client-9999.ebuild

@@ -23,14 +23,27 @@ SLOT="0"
 
 IUSE=""
 
-DEPEND=">=dev-libs/protobuf-3.0.0"
+DEPEND=">=dev-libs/protobuf-3.0.0
-RDEPEND="${DEPEND}"
+        dev-util/cmake"
+RDEPEND=">=dev-libs/protobuf-3.0.0"
 
 src_unpack() {
 	cros-workon_src_unpack "$@"
 	cargo_src_unpack "$@"
 }
 
+src_prepare() {
+	# fero-client uses the grpcio-sys-0.2.3 Rust crate (amond others, see CRATES)
+	# grpcio-sys-0.2.3 needs a patch to compile against >=glibc-2.30.
+	# The crates's sources are put in ECARGO_HOME so we need to change
+	# directories before applying the patch.
+	local cwd="$(pwd)"
+	cd "${ECARGO_HOME}"
+	eapply -p0 "${FILESDIR}/0001-gettid-glibc-2.30.patch"
+	eapply_user
+	cd "$cwd"
+}
+
 src_compile() {
 	export CARGO_HOME="${ECARGO_HOME}"
 	cargo build -v -j $(makeopts_jobs) $(usex debug "" --release) -p ${PN} \

sdk_container/src/third_party/coreos-overlay/coreos-devel/fero-client/files/0001-gettid-glibc-2.30.patch

@@ -0,0 +1,34 @@
+grpcio-sys-0.2.3 defines its own gettid() function which conflicts with gettid()
+shipped with glibc-2.30 and above. So we only define that function if
+glibc < 2.30.
+
+Fixes:
+grpcio-sys-0.2.3/grpc/src/core/lib/support/log_linux.c:42:13: error: conflicting types for 'gettid'
+     42 | static long gettid(void) { return syscall(__NR_gettid); }
+        |             ^~~~~~
+  In file included from /usr/include/unistd.h:1187,
+                   from grpcio-sys-0.2.3/grpc/src/core/lib/support/log_linux.c:40:
+  /usr/include/bits/unistd_ext.h:34:16: note: previous declaration of 'gettid' was here
+     34 | extern __pid_t gettid (void) __THROW;
+        |                ^~~~~~
+
+--- gentoo/grpcio-sys-0.2.3/grpc/src/core/lib/support/log_linux.c   2020-11-23 18:29:18.053038547 +0000
++++ gentoo/grpcio-sys-0.2.3/grpc/src/core/lib/support/log_linux.c    2020-11-23 18:32:39.502926134 +0000
+@@ -39,7 +39,17 @@
+ #include <time.h>
+ #include <unistd.h>
+ 
++/* glibc-2.30 and above ship gettid */
++#define NEED_GETTID 1
++#if defined(__GLIBC_PREREQ)
++#   if __GLIBC_PREREQ(2,30)
++#      define NEED_GETTID 0
++#   endif
++#endif
++
++#if NEED_GETTID
+ static long gettid(void) { return syscall(__NR_gettid); }
++#endif
+ 
+ void gpr_log(const char *file, int line, gpr_log_severity severity,
+              const char *format, ...) {