diff --git a/README.adoc b/README.adoc
index 044cc34..727ba0c 100644
--- a/README.adoc
+++ b/README.adoc
@@ -13584,6 +13584,7 @@ It was not possible to disable the symlinks automatically for the entire project
 
 The horrendous downsides of this are:
 
+* It is likely preventing <<ccache>> hits when building to different output paths, because it makes the `-I` includes point to different paths. This is especially important for <<gem5-ruby-build>>, which could have the exact same source files as the non-Ruby builds: https://stackoverflow.com/questions/60340271/can-ccache-handle-symlinks-to-the-same-input-source-file-as-hits
 * when <<debug-the-emulator,debugging the emulator>>, it shows you directories inside the build directory rather than in the source tree
 * it is harder to separate which files are <<gem5-code-generation,generated>> and which are in-tree when grepping for code generated definitions