This was introduced recently to Clang and it fails for:

  glslang/MachineIndependent/Scan.cpp:197:17: error: misleading indentation; statement is not part of the previous 'else'

BUILD.gn

diff --git a/BUILD.gn b/BUILD.gn
index 098d7de..2233e0d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -183,6 +183,8 @@
       "-Wno-unused-variable",
       "-Wno-missing-field-initializers",
       "-Wno-newline-eof",
+      "-Wno-unknown-warning-option",
+      "-Wno-misleading-indentation",
     ]
   }
   if (is_win && !is_clang) {