test-many-klibcs: Add comment about script dependencies
diff --git a/test-many-klibcs b/test-many-klibcs
index 47a7fc5..7b052ef 100755
--- a/test-many-klibcs
+++ b/test-many-klibcs
@@ -1,5 +1,10 @@
 #!/bin/bash -eu
 
+# This requires:
+# * Cross-toolchains (gcc-$gnuarch)
+# * QEMU user-space static binaries (qemu-user-static)
+# * sudo
+
 build() {
     echo "I: Using $("$gnuarch-gcc" --version | head -1)"
     echo "I: Using $("$gnuarch-ld" --version | head -1)"