From 51d73173a87f7115284f63e0f466a3ca7c0d9721 Mon Sep 17 00:00:00 2001
From: Michael Dusan <michael.dusan@gmail.com>
Date: Sun, 21 Jul 2019 00:16:56 -0400
Subject: [PATCH] Updated FAQ (markdown)

---
 FAQ.md | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/FAQ.md b/FAQ.md
index d2d1b91..8dc89ff 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -28,4 +28,22 @@ const matrix = Matrix{1.0, 0.0, 0.0, 0.0,
                       0.0, 0.0, 1.0, 0.0,
                       0.0, 0.0, 0.0, 1.0};
 // zig fmt: on
-```
\ No newline at end of file
+```
+
+## Explain this error: `Unable to create builtin.zig: access denied`
+
+When building or compiling with Zig a build-cache is used.
+This particular error indicates filesystem security has prevented access
+to a directory or file used in the *global* build-cache.
+Fixing permissions should solve the issue.
+
+note: It is safe to manually remove cache directories when no zig compiler process is active.
+
+As of Zig 0.4.0 the build cache can be found in the following locations unless overridden with command-line options:
+
+TYPE | OS | DIRECTORY
+:-: | :-: | ---
+global | linux | $HOME/.local/share/zig
+|| macOS | $HOME/Library/Application Support/zig
+|| Windows | %LOCALAPPDATA%\zig
+local | all | $PWD/zig-cache
\ No newline at end of file