From 17db3179169f9733d0050054fcb37b6525c217f4 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Sat, 31 Aug 2024 09:42:39 -0700
Subject: [PATCH] build: build without Git, tag version as dev with 0 SHA

Fixes #2170

Example now: `info: ghostty version=0.1.0-dev+0000000`
---
 build.zig             | 13 ++++++++++++-
 src/build/Version.zig | 27 ++++++++++++++++++++++++---
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/build.zig b/build.zig
index bc829d59e..b448e583a 100644
--- a/build.zig
+++ b/build.zig
@@ -177,7 +177,18 @@ pub fn build(b: *std.Build) !void {
     config.version = if (version_string) |v|
         try std.SemanticVersion.parse(v)
     else version: {
-        const vsn = try Version.detect(b);
+        const vsn = Version.detect(b) catch |err| switch (err) {
+            // If Git isn't available we just make an unknown dev version.
+            error.GitNotFound => break :version .{
+                .major = app_version.major,
+                .minor = app_version.minor,
+                .patch = app_version.patch,
+                .pre = "dev",
+                .build = "0000000",
+            },
+
+            else => return err,
+        };
         if (vsn.tag) |tag| {
             // Tip releases behave just like any other pre-release so we skip.
             if (!std.mem.eql(u8, tag, "tip")) {
diff --git a/src/build/Version.zig b/src/build/Version.zig
index 6c1bbc717..df6585a8e 100644
--- a/src/build/Version.zig
+++ b/src/build/Version.zig
@@ -19,14 +19,34 @@ branch: []const u8,
 pub fn detect(b: *std.Build) !Version {
     // Execute a bunch of git commands to determine the automatic version.
     var code: u8 = 0;
-    const branch = try b.runAllowFail(&[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "rev-parse", "--abbrev-ref", "HEAD" }, &code, .Ignore);
+    const branch: []const u8 = b.runAllowFail(
+        &[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "rev-parse", "--abbrev-ref", "HEAD" },
+        &code,
+        .Ignore,
+    ) catch |err| switch (err) {
+        error.FileNotFound => return error.GitNotFound,
+        else => return err,
+    };
 
     const short_hash = short_hash: {
-        const output = try b.runAllowFail(&[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "log", "--pretty=format:%h", "-n", "1" }, &code, .Ignore);
+        const output = b.runAllowFail(
+            &[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "log", "--pretty=format:%h", "-n", "1" },
+            &code,
+            .Ignore,
+        ) catch |err| switch (err) {
+            error.FileNotFound => return error.GitNotFound,
+            else => return err,
+        };
+
         break :short_hash std.mem.trimRight(u8, output, "\r\n ");
     };
 
-    const tag = b.runAllowFail(&[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "describe", "--exact-match", "--tags" }, &code, .Ignore) catch |err| switch (err) {
+    const tag = b.runAllowFail(
+        &[_][]const u8{ "git", "-C", b.build_root.path orelse ".", "describe", "--exact-match", "--tags" },
+        &code,
+        .Ignore,
+    ) catch |err| switch (err) {
+        error.FileNotFound => return error.GitNotFound,
         error.ExitCodeFailure => "", // expected
         else => return err,
     };
@@ -39,6 +59,7 @@ pub fn detect(b: *std.Build) !Version {
         "--quiet",
         "--exit-code",
     }, &code, .Ignore) catch |err| switch (err) {
+        error.FileNotFound => return error.GitNotFound,
         error.ExitCodeFailure => {}, // expected
         else => return err,
     };