diff --git a/pkgs/development/compilers/llvm/12/clang/default.nix b/pkgs/development/compilers/llvm/12/clang/default.nix
index d4d0ddf7954d..d90d019e6d51 100644
--- a/pkgs/development/compilers/llvm/12/clang/default.nix
+++ b/pkgs/development/compilers/llvm/12/clang/default.nix
@@ -8,7 +8,7 @@ let
     pname = "clang";
     inherit version;
 
-    src = fetch "clang" "11ay72f81ffygil5ficq7mzplck4gffm77p0yj4ib3dgiqbb1qbw";
+    src = fetch "clang" "185r9rr254v75ja33nmm53j85lcnkj7bzsl18wvnd37jmz2nfxa5";
     inherit clang-tools-extra_src;
 
     unpackPhase = ''
diff --git a/pkgs/development/compilers/llvm/12/compiler-rt.nix b/pkgs/development/compilers/llvm/12/compiler-rt.nix
index 9721879d762b..e6ac77b7d265 100644
--- a/pkgs/development/compilers/llvm/12/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/12/compiler-rt.nix
@@ -11,7 +11,7 @@ in
 stdenv.mkDerivation rec {
   pname = "compiler-rt";
   inherit version;
-  src = fetch pname "01dvir3858qkjmqhw2h6jjagq0la0kasnwzqbyv91yixnwx8369z";
+  src = fetch pname "1x0z875nbdpzhr4qb7linm6r9swvdf6dvwqy1s22pbn4wdcw0cvf";
 
   nativeBuildInputs = [ cmake python3 llvm ];
   buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
diff --git a/pkgs/development/compilers/llvm/12/default.nix b/pkgs/development/compilers/llvm/12/default.nix
index 901e9c82eee5..593db716ac6b 100644
--- a/pkgs/development/compilers/llvm/12/default.nix
+++ b/pkgs/development/compilers/llvm/12/default.nix
@@ -8,7 +8,7 @@
 
 let
   release_version = "12.0.0";
-  candidate = "rc4"; # empty or "rcN"
+  candidate = "rc5"; # empty or "rcN"
   dash-candidate = lib.optionalString (candidate != "") "-${candidate}";
   version = "${release_version}${dash-candidate}"; # differentiating these (variables) is important for RCs
   targetConfig = stdenv.targetPlatform.config;
@@ -18,7 +18,7 @@ let
     inherit sha256;
   };
 
-  clang-tools-extra_src = fetch "clang-tools-extra" "1m1qga8m967bzqkxwx9xqkw1lkxi9dhlrn6km2k7g2yqyb6k14ag";
+  clang-tools-extra_src = fetch "clang-tools-extra" "1hga9k5m60ywmr7m69jf1v6vj1ra1n6ybv1abzlz94f5q22i1a02";
 
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
diff --git a/pkgs/development/compilers/llvm/12/libc++/default.nix b/pkgs/development/compilers/llvm/12/libc++/default.nix
index e910d2c96b68..757651c0f4c2 100644
--- a/pkgs/development/compilers/llvm/12/libc++/default.nix
+++ b/pkgs/development/compilers/llvm/12/libc++/default.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation {
   pname = "libc++";
   inherit version;
 
-  src = fetch "libcxx" "0ai91zls1738502c3b2frhawmjpi73rm3m677hh540wrjp3xv0ql";
+  src = fetch "libcxx" "01abh553dvjgk5cjzzp0ghmg00laqbr4ar4frdhyhpbwhhmwc880";
 
   postUnpack = ''
     unpackFile ${libcxxabi.src}
diff --git a/pkgs/development/compilers/llvm/12/libc++abi.nix b/pkgs/development/compilers/llvm/12/libc++abi.nix
index 70dd5af7277a..e35480c7bf24 100644
--- a/pkgs/development/compilers/llvm/12/libc++abi.nix
+++ b/pkgs/development/compilers/llvm/12/libc++abi.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation {
   pname = "libc++abi";
   inherit version;
 
-  src = fetch "libcxxabi" "02qp6ndagq7n48p53z93d1rrx0v0v4rsahd4vkv5frid0vm4ah9h";
+  src = fetch "libcxxabi" "0mjj4f63ix4j1b72bgzpcki7mzf3qszrq7snqhiq0c5s73skkwx0";
 
   nativeBuildInputs = [ cmake python3 ];
   buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm) libunwind;
diff --git a/pkgs/development/compilers/llvm/12/libunwind.nix b/pkgs/development/compilers/llvm/12/libunwind.nix
index ddfcf508fd8d..83e76c0c56cd 100644
--- a/pkgs/development/compilers/llvm/12/libunwind.nix
+++ b/pkgs/development/compilers/llvm/12/libunwind.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation rec {
   pname = "libunwind";
   inherit version;
 
-  src = fetch pname "1a5db1lxw98a430b8mnaclc0w98y6cc8k587kgjhn0nghl40l40i";
+  src = fetch pname "0kaq75ygzv9dqfsx27pi5a0clipdjq6a9vghhb89d8k1rf20lslh";
 
   postUnpack = ''
     unpackFile ${libcxx.src}
diff --git a/pkgs/development/compilers/llvm/12/lld.nix b/pkgs/development/compilers/llvm/12/lld.nix
index 00e30e16b6b0..a5e4ab834ecf 100644
--- a/pkgs/development/compilers/llvm/12/lld.nix
+++ b/pkgs/development/compilers/llvm/12/lld.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
-  src = fetch pname "0r9pxhvinipirv9s5k8fnsnqd30zfniwqjkvw5sac3lq29rn2lp1";
+  src = fetch pname "044lv1d9am2xmbc3pvssxkkiyxyv72n2xkgk8z3p9k72h3ay00q3";
 
   nativeBuildInputs = [ cmake ];
   buildInputs = [ llvm libxml2 ];
diff --git a/pkgs/development/compilers/llvm/12/lldb.nix b/pkgs/development/compilers/llvm/12/lldb.nix
index f9f978c60b1f..67de0c187415 100644
--- a/pkgs/development/compilers/llvm/12/lldb.nix
+++ b/pkgs/development/compilers/llvm/12/lldb.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation (rec {
   pname = "lldb";
   inherit version;
 
-  src = fetch pname "0943gan83mldizwbhksd07w4h90z4djjpv5f8v49caz8y9113svg";
+  src = fetch pname "0q4p4s5ws1zszs3i4da5w5fnxkpny0q3fr1s1sh7jp9wcwxbxiqq";
 
   patches = [ ./lldb-procfs.patch ];
 
diff --git a/pkgs/development/compilers/llvm/12/llvm.nix b/pkgs/development/compilers/llvm/12/llvm.nix
index f70c4379c1af..6e6127ba9494 100644
--- a/pkgs/development/compilers/llvm/12/llvm.nix
+++ b/pkgs/development/compilers/llvm/12/llvm.nix
@@ -32,8 +32,8 @@ in stdenv.mkDerivation (rec {
   pname = "llvm";
   inherit version;
 
-  src = fetch pname "1jif65i165h41cfcsfvfjy5k1yrnikg61assj5vs0f25pv1vbyvf";
-  polly_src = fetch "polly" "0hk6j6rsal3zsp1f9fla71yzbwmzz9007m63x22hy7qfiwyplvf2";
+  src = fetch pname "088dyv7hppidl3rqfsjdibvn4d3a74896fg2sz4dwaxlg19way93";
+  polly_src = fetch "polly" "1qj7gkfr1yrsrz6j086l9p6d2kyyln15fmfiab4isn96g1dhsfb5";
 
   unpackPhase = ''
     unpackFile $src
diff --git a/pkgs/development/compilers/llvm/12/openmp.nix b/pkgs/development/compilers/llvm/12/openmp.nix
index fcb91574d17d..1e4618e4a1b4 100644
--- a/pkgs/development/compilers/llvm/12/openmp.nix
+++ b/pkgs/development/compilers/llvm/12/openmp.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   pname = "openmp";
   inherit version;
 
-  src = fetch pname "07g2rsfhli3szv3chzy6y37p2176ywdb6w3k2fv9g2r416cpxjdz";
+  src = fetch pname "1d16r5whjb2n4n28rg8wn2g9krlc92q6nb0qmnnbzhqhx0rbkjfb";
 
   nativeBuildInputs = [ cmake perl ];
   buildInputs = [ llvm ];