add: zig and build.sh

build systems

toolchain/examples/buildsh-demo/buildsh-demo.recipe

@@ -0,0 +1,23 @@
+-- buildsh-demo.recipe — demonstrates build_system = "build.sh".
+--
+-- The build.sh build system runs the source tree's build.sh script from the
+-- extracted source directory. The script receives $DESTDIR pointing at the
+-- staging tree where installed files must be placed, exactly like the
+-- 'custom' build system — but the script name is fixed to build.sh.
+--
+-- To try this:
+--   1. Unpack the source tarball:  tar -xzf buildsh-tool-1.0.tar.gz
+--   2. Run the script manually:     cd buildsh-tool-1.0 && DESTDIR=/tmp/stage sh build.sh
+--   3. Inspect the staged output:   find /tmp/stage
+--   4. Build with makepkg:          zeta-makepkg buildsh-demo.recipe
+
+return {
+  name         = "buildsh-tool",
+  version      = "1.0",
+  summary      = "Example build.sh-style package (shell-installed binary)",
+  url          = "buildsh-tool-1.0.tar.gz",
+  sha256       = nil,
+  deps         = {},
+  build_system = "build.sh",
+  test         = "test -x ${DESTDIR}/usr/bin/buildsh-tool",
+}