Document build issues related non-default compilers
Change-Id: I595a4b8fc4d82ba410d758b077fddec01edd6fe3
diff --git a/src/source/known-issues.md b/src/source/known-issues.md
index 4b3d3ca..1643055 100644
--- a/src/source/known-issues.md
+++ b/src/source/known-issues.md
@@ -109,3 +109,17 @@
Project.
**Fix**: None.
+
+## Build errors related to using the wrong compiler. ##
+
+**Symptom**: The build fails with various symptoms. One
+such symptom is `cc1: error: unrecognized command line option "-m32"`
+
+**Cause**: The Android build system uses the default compiler
+in the PATH, assuming it's a suitable compiler to generate
+binaries that run on the host. Other situations (e.g. using
+the Android NDK or building the kernel) cause the default
+compiler to not be a host compiler.
+
+**Fix**: Use a "clean" shell, in which no previous
+actions could have swapped the default compiler.
