diff --git a/debian/changelog b/debian/changelog
index 042854ef..7fecb263 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -331,6 +331,30 @@ llvm-toolchain-snapshot (1:13~++20210129063721+010b176cdefb-1~exp1) experimental
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Sat, 30 Jan 2021 17:31:15 +0100
 
+llvm-toolchain-12 (1:12.0.1-19) UNRELEASED; urgency=medium
+
+  * Build clangd with GRPC support
+    Thanks to Sam McCall for the patch
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Sat, 29 Jan 2022 10:17:38 +0100
+
+llvm-toolchain-12 (1:12.0.1-18) unstable; urgency=medium
+
+  * Unbreak llvm-toolchain-12 on buster.
+    -fuse-ld=gold wasn't passed to compiler-rt. it was using bfd.
+    And binutils shipping in buster has a bug preventing this to work:
+    https://github.com/llvm/llvm-project/issues/42339
+  * Rename ocaml-nox => ocaml-base (Closes: #1002608)
+  * Remove Build-Conflicts: ocaml
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Thu, 16 Dec 2021 17:49:22 +0100
+
+llvm-toolchain-12 (1:12.0.1-17) unstable; urgency=medium
+
+  * Rebuild to workaround the coinstallability issue (Closes: #996858)
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Tue, 30 Nov 2021 19:32:51 +0100
+
 llvm-toolchain-12 (1:12.0.1-16) unstable; urgency=medium
 
   [ Erik Maciejewski ]
diff --git a/debian/control b/debian/control
index 2a7c56ad..05e4df58 100644
--- a/debian/control
+++ b/debian/control
@@ -23,7 +23,8 @@ Build-Depends: debhelper (>= 10.0), cmake, ninja-build,
     dh-exec, dh-ocaml [amd64 arm64 armhf ppc64el riscv64 s390x],
     libpfm4-dev [linux-any], python3-setuptools, libz3-dev,
     llvm-spirv [ amd64 arm64 armel armhf mips64el mipsel ppc64el s390x ] <!stage1> | hello [!i386],
-    spirv-tools [ linux-any ] | hello [ !i386]
+    spirv-tools [ linux-any ] | hello [ !i386],
+    libgrpc++-dev, libprotobuf-dev, protobuf-compiler, protobuf-compiler-grpc
 # "| hello" is for older buster/bionic distros without spirv support
 Build-Conflicts: oprofile
 Standards-Version: 4.2.1
diff --git a/debian/rules b/debian/rules
index 5d51b4ba..cad7f5a5 100755
--- a/debian/rules
+++ b/debian/rules
@@ -124,6 +124,18 @@ ZARCH=z13
 endif
 STAGE_2_CMAKE_EXTRA += -DCLANG_SYSTEMZ_DEFAULT_ARCH=$(ZARCH)
 
+# clangd remote index support requires GRPC & protobuf.
+# Enable if minimum tested versions are available.
+ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' libgrpc++-dev) gt 1.30.0; echo $$?),0)
+ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' protobuf-compiler-grpc) gt 1.30.0; echo $$?),0)
+ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' libprotobuf-dev) gt 3.12.0; echo $$?),0)
+ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' protobuf-compiler) gt 3.12.0; echo $$?),0)
+STAGE_2_CMAKE_EXTRA += -DCLANGD_ENABLE_REMOTE=ON
+endif
+endif
+endif
+endif
+
 export CC=gcc-$(GCC_VERSION)
 export CXX=g++-$(GCC_VERSION)
 
@@ -406,6 +418,8 @@ preconfigure:
 	@echo "LLVM_VERSION=$(LLVM_VERSION)"
 	@echo "LLVM_VERSION_FULL=$(LLVM_VERSION_FULL)"
 	@echo "LLVM_VERSION_SNAPSHOT=$(LLVM_VERSION_SNAPSHOT)"
+	@echo "PATH=$(PATH)"
+	@echo "LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)"
 
 	for f in debian/*.in; do \
 		f2=$$(echo $$f | sed 's/\.in$$//;s/X\.Y/$(LLVM_VERSION)/'); \
@@ -679,7 +693,7 @@ override_dh_auto_install:
 	# Clean up temporary files to make sure the install works
 	rm -rf $(find $(TARGET_BUILD) -wholename '*CMakeFiles*' -not -name CMakeLists.txt -a -name "*.dir" -type d)
 	# install/fast enables a make install without recompiling temporary files
-	DESTDIR=$(DEB_INST)/ ninja -C $(TARGET_BUILD) $(VERBOSE) stage2-install
+	LD_LIBRARY_PATH=$(STAGE_2_LIB_DIR) DESTDIR=$(DEB_INST)/ ninja -C $(TARGET_BUILD) $(VERBOSE) stage2-install
 
 	# Not used on Linux.
 	rm -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/bin/argdumper
@@ -691,6 +705,9 @@ override_dh_auto_install:
 	# Remove an example - introduced in https://reviews.llvm.org/D61446
 	rm -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/libBye.a
 
+	# Remove unused clangd lib
+	rm -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/libRemoteIndexProto.a $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/libRemoteIndexServiceProto.a
+
 	cp $(TARGET_BUILD_STAGE2)/bin/clang-query $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/bin
 
 	# Only run on executable, not script