diff --git a/pkgs/development/compilers/llvm/12/clang/default.nix b/pkgs/development/compilers/llvm/12/clang/default.nix
index d90d019e6d5..169f2f27306 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" "185r9rr254v75ja33nmm53j85lcnkj7bzsl18wvnd37jmz2nfxa5";
+    src = fetch "clang" "1vd9rhhrd8ghdg111lac7w8by71y9l14yh5zxfijsm6lj4p4avp2";
     inherit clang-tools-extra_src;
 
     unpackPhase = ''
diff --git a/pkgs/development/compilers/llvm/12/compiler-rt/default.nix b/pkgs/development/compilers/llvm/12/compiler-rt/default.nix
index e6ac77b7d26..e4c2295a0d7 100644
--- a/pkgs/development/compilers/llvm/12/compiler-rt/default.nix
+++ b/pkgs/development/compilers/llvm/12/compiler-rt/default.nix
@@ -11,7 +11,7 @@ in
 stdenv.mkDerivation rec {
   pname = "compiler-rt";
   inherit version;
-  src = fetch pname "1x0z875nbdpzhr4qb7linm6r9swvdf6dvwqy1s22pbn4wdcw0cvf";
+  src = fetch pname "0d444qihq9jhqnfv003cr704v363va72zl6qaw2algj1c85cva45";
 
   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 ad7121c36a8..c3e9cc5b499 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 = "rc5"; # empty or "rcN"
+  candidate = ""; # 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" "1hga9k5m60ywmr7m69jf1v6vj1ra1n6ybv1abzlz94f5q22i1a02";
+  clang-tools-extra_src = fetch "clang-tools-extra" "0p3dzr0qa7mar83y66xa5m5apynf6ia0lsdsq6axwnm64ysy0hdd";
 
   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 757651c0f4c..ef845e0f7b0 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" "01abh553dvjgk5cjzzp0ghmg00laqbr4ar4frdhyhpbwhhmwc880";
+  src = fetch "libcxx" "1wf3ww29xkx7prs7pdwicy5qqfapib26110jgmkjrbka9z57bjvx";
 
   postUnpack = ''
     unpackFile ${libcxxabi.src}
diff --git a/pkgs/development/compilers/llvm/12/libc++abi/default.nix b/pkgs/development/compilers/llvm/12/libc++abi/default.nix
index c5e9aa954b3..6aff7872753 100644
--- a/pkgs/development/compilers/llvm/12/libc++abi/default.nix
+++ b/pkgs/development/compilers/llvm/12/libc++abi/default.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation {
   pname = "libc++abi";
   inherit version;
 
-  src = fetch "libcxxabi" "0mjj4f63ix4j1b72bgzpcki7mzf3qszrq7snqhiq0c5s73skkwx0";
+  src = fetch "libcxxabi" "1cbmzspwjlr8f6sp73pw6ivf4dpg6rpc61by0q1m2zca2k6yif3a";
 
   nativeBuildInputs = [ cmake python3 ];
   buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm) libunwind;
diff --git a/pkgs/development/compilers/llvm/12/libunwind/default.nix b/pkgs/development/compilers/llvm/12/libunwind/default.nix
index 83e76c0c56c..56ee98176d2 100644
--- a/pkgs/development/compilers/llvm/12/libunwind/default.nix
+++ b/pkgs/development/compilers/llvm/12/libunwind/default.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation rec {
   pname = "libunwind";
   inherit version;
 
-  src = fetch pname "0kaq75ygzv9dqfsx27pi5a0clipdjq6a9vghhb89d8k1rf20lslh";
+  src = fetch pname "1x8wpmsrsgnwj2v5ih52ylni7r6n8gzkcj6hx65zbxski2rablly";
 
   postUnpack = ''
     unpackFile ${libcxx.src}
diff --git a/pkgs/development/compilers/llvm/12/lld/default.nix b/pkgs/development/compilers/llvm/12/lld/default.nix
index a5e4ab834ec..1d983f13c0f 100644
--- a/pkgs/development/compilers/llvm/12/lld/default.nix
+++ b/pkgs/development/compilers/llvm/12/lld/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
-  src = fetch pname "044lv1d9am2xmbc3pvssxkkiyxyv72n2xkgk8z3p9k72h3ay00q3";
+  src = fetch pname "1zakyxk5bwnh7jarckcd4rbmzi58jgn2dbah5j5cwcyfyfbx9drc";
 
   nativeBuildInputs = [ cmake ];
   buildInputs = [ llvm libxml2 ];
diff --git a/pkgs/development/compilers/llvm/12/lldb/default.nix b/pkgs/development/compilers/llvm/12/lldb/default.nix
index 67de0c18741..7996487a2a8 100644
--- a/pkgs/development/compilers/llvm/12/lldb/default.nix
+++ b/pkgs/development/compilers/llvm/12/lldb/default.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation (rec {
   pname = "lldb";
   inherit version;
 
-  src = fetch pname "0q4p4s5ws1zszs3i4da5w5fnxkpny0q3fr1s1sh7jp9wcwxbxiqq";
+  src = fetch pname "1v85qyq3snk81vjmwq5q7xikyyqsfpqy2c4qmr81mps4avsw1g0l";
 
   patches = [ ./lldb-procfs.patch ];
 
diff --git a/pkgs/development/compilers/llvm/12/llvm/default.nix b/pkgs/development/compilers/llvm/12/llvm/default.nix
index 6075f9d8d55..351b5b87940 100644
--- a/pkgs/development/compilers/llvm/12/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/12/llvm/default.nix
@@ -32,8 +32,8 @@ in stdenv.mkDerivation (rec {
   pname = "llvm";
   inherit version;
 
-  src = fetch pname "088dyv7hppidl3rqfsjdibvn4d3a74896fg2sz4dwaxlg19way93";
-  polly_src = fetch "polly" "1qj7gkfr1yrsrz6j086l9p6d2kyyln15fmfiab4isn96g1dhsfb5";
+  src = fetch pname "0l4b79gwfvxild974aigcq1yigypjsk2j5p59syhl6ksd744gp29";
+  polly_src = fetch "polly" "1ixl9yj526n8iqh9ckyiah2vzravs9d1akybqq7rvy32n9vgr6hd";
 
   unpackPhase = ''
     unpackFile $src
diff --git a/pkgs/development/compilers/llvm/12/openmp.nix b/pkgs/development/compilers/llvm/12/openmp.nix
index 1e4618e4a1b..07c1c2b0aed 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 "1d16r5whjb2n4n28rg8wn2g9krlc92q6nb0qmnnbzhqhx0rbkjfb";
+  src = fetch pname "0z8n1wanby6aq3i7d91mgk72hb33zfl5blayk0a22cs7l8i706zb";
 
   nativeBuildInputs = [ cmake perl ];
   buildInputs = [ llvm ];