package: Cache build artifacts locally for zig run and test

> Secondarily, while I appreciate that check really makes sure that Zig works, the way it's implemented currently litters the default Zig cache (located under $HOME by default) with build products. If I may suggest, isolating Zig to either not use a build cache at all or to keep it confined to the build environment would be preferrable.
> - @paulsnar (on AUR)

Luckily paulsnar fixed his own bug report, by emailing me a patch ;)

Unfortunately, there is no way to disable caching right now
(see zig issue #12317), so using a local cache is the best option.

Elaborated-by: Techcable <Techcable@techcable.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/PKGBUILD b/PKGBUILD
index daf4da3c6fd5..6dae8db3a9c8 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -79,11 +79,17 @@ RELATIVE_LANGREF_FILE="docs/langref.html";
 RELATIVE_STDLIB_DOC_FILES=("docs/std/index.html" "docs/std/main.js" "docs/std/data.js");
 check() {
     hello_file="$(realpath ../hello.zig)"
+    # Zig caches (both local and global) can use up a lot of space.
+    # For these hello world examples (in a frequently updated package), this is very wasteful.
+    #
+    # Right now there is no way to disable the cache (see Zig issue #12317)
+    # Instead we shove everything in a local directory
+    cache_dir="${srcdir}/zig-cache"
     cd "${srcdir}/zig-linux-${CARCH}-${pkgver//_/-}";
     echo "Running Zig Hello World"
-    ./zig run "$hello_file"
-    ./zig test "$hello_file"
-    echo "Checking for docs...."
+    ./zig run --cache-dir "$cache_dir" --global-cache-dir "$cache_dir" "$hello_file"
+    ./zig test --cache-dir "$cache_dir" --global-cache-dir "$cache_dir" "$hello_file"
+    rm -rf "$cache_dir";
     local missing_docs=();
     # Zig has had long-running issues with the location
     # of the docs directory.