build: Add a new snap option and use it to build the snap

So we can limit the snap operations even at build time

snap/snapcraft.yaml

@@ -79,7 +79,12 @@ parts:
     # TODO: Remove -fno-sys=gtk4-layer-shell when we upgrade to a version that packages it Ubuntu 24.10+
     override-build: |
       craftctl set version=$(cat VERSION)
-      $CRAFT_PART_SRC/../../zig/src/zig build -Dpatch-rpath=\$ORIGIN/../usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR:/snap/core24/current/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR -Doptimize=ReleaseFast -Dcpu=baseline -fno-sys=gtk4-layer-shell
+      $CRAFT_PART_SRC/../../zig/src/zig build \
+        -Dsnap=true \
+        -Dpatch-rpath=\$ORIGIN/../usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR:/snap/core24/current/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR \
+        -Doptimize=ReleaseFast \
+        -Dcpu=baseline \
+        -fno-sys=gtk4-layer-shell
       cp -rp zig-out/* $CRAFT_PART_INSTALL/
       sed -i 's|Icon=com.mitchellh.ghostty|Icon=${SNAP}/share/icons/hicolor/512x512/apps/com.mitchellh.ghostty.png|g' $CRAFT_PART_INSTALL/share/applications/com.mitchellh.ghostty.desktop
 

src/apprt/gtk/class/surface.zig

@@ -9,6 +9,7 @@ const gobject = @import("gobject");
 const gtk = @import("gtk");
 
 const apprt = @import("../../../apprt.zig");
+const build_config = @import("../../../build_config.zig");
 const datastruct = @import("../../../datastruct/main.zig");
 const font = @import("../../../font/main.zig");
 const input = @import("../../../input.zig");
@@ -1227,8 +1228,10 @@ pub const Surface = extern struct {
 
         // Unset environment varies set by snaps if we're running in a snap.
         // This allows Ghostty to further launch additional snaps.
-        if (env.get("SNAP")) |_| {
-            try filterSnapPaths(alloc, &env);
+        if (comptime build_config.snap) {
+            if (env.get("SNAP")) |_| {
+                try filterSnapPaths(alloc, &env);
+            }
         }
 
         // This is a hack because it ties ourselves (optionally) to the

src/build/Config.zig

@@ -51,6 +51,7 @@ patch_rpath: ?[]const u8 = null,
 
 /// Artifacts
 flatpak: bool = false,
+snap: bool = false,
 emit_bench: bool = false,
 emit_docs: bool = false,
 emit_exe: bool = false,
@@ -152,6 +153,12 @@ pub fn init(b: *std.Build) !Config {
         "Build for Flatpak (integrates with Flatpak APIs). Only has an effect targeting Linux.",
     ) orelse false;
 
+    config.snap = b.option(
+        bool,
+        "snap",
+        "Build for Snap (do specific Snap operations). Only has an effect targeting Linux.",
+    ) orelse false;
+
     config.sentry = b.option(
         bool,
         "sentry",
@@ -442,6 +449,7 @@ pub fn addOptions(self: *const Config, step: *std.Build.Step.Options) !void {
     // We need to break these down individual because addOption doesn't
     // support all types.
     step.addOption(bool, "flatpak", self.flatpak);
+    step.addOption(bool, "snap", self.snap);
     step.addOption(bool, "x11", self.x11);
     step.addOption(bool, "wayland", self.wayland);
     step.addOption(bool, "sentry", self.sentry);
@@ -506,6 +514,7 @@ pub fn fromOptions() Config {
         .app_runtime = std.meta.stringToEnum(ApprtRuntime, @tagName(options.app_runtime)).?,
         .font_backend = std.meta.stringToEnum(FontBackend, @tagName(options.font_backend)).?,
         .renderer = std.meta.stringToEnum(RendererBackend, @tagName(options.renderer)).?,
+        .snap = options.snap,
         .exe_entrypoint = std.meta.stringToEnum(ExeEntrypoint, @tagName(options.exe_entrypoint)).?,
         .wasm_target = std.meta.stringToEnum(WasmTarget, @tagName(options.wasm_target)).?,
         .wasm_shared = options.wasm_shared,

src/build_config.zig

@@ -38,6 +38,7 @@ pub const artifact = Artifact.detect();
 const config = BuildConfig.fromOptions();
 pub const exe_entrypoint = config.exe_entrypoint;
 pub const flatpak = options.flatpak;
+pub const snap = options.snap;
 pub const app_runtime: apprt.Runtime = config.app_runtime;
 pub const font_backend: font.Backend = config.font_backend;
 pub const renderer: rendererpkg.Backend = config.renderer;