diff --git a/kiss b/kiss
index 0d267a1..0633af3 100755
--- a/kiss
+++ b/kiss
@@ -855,9 +855,14 @@ pkg_build() {
     # Call the build script, log the output to the terminal and to a file.
     # There's no PIPEFAIL in POSIX shell so we must resort to tricks like kill.
     {
-        # Give the script a modified environment. Define CC and CXX giving them
-        # the generic values cc and c++. Define KISS_ROOT sanitized to ensure
-        # safe path joining in build files.
+        # Give the script a modified environment. Define toolchain program
+        # environment variables assuming a generic environment by default.
+        #
+        # Define DESTDIR, PREFIX and GOPATH to sane defaults as their use is
+        # mandatory in anything using autotools, meson, cmake, etc.
+        #
+        # Define KISS_ROOT as the sanitized value used internally by the
+        # package manager. This is safe to join with other paths.
         AR="${AR:-ar}" \
         CC="${CC:-cc}" \
         CXX="${CXX:-c++}" \