Add support for linux gnu build targets (#741)

INSTALL.md

@@ -5,11 +5,16 @@ We use [`zig`][zig] to build Vere, which is packaged as a single binary,
 
 ## Supported Targets
 
+Main (`-Dall`) targets:
 - `aarch64-linux-musl`
 - `x86_64-linux-musl`
 - `aarch64-macos`
 - `x86_64-macos`
 
+Additional targets:
+- `aarch64-linux-gnu`
+- `x86_64-linux-gnu`
+
 ## Prerequisites
 
 Install version 0.13.0 of `zig` with the package manager of your choosing, e.g., `brew install zig`, or download the binary from [here][zig-download].

build.zig

@@ -2,13 +2,20 @@ const std = @import("std");
 
 const VERSION = "3.2";
 
-const targets: []const std.Target.Query = &.{
+const main_targets = .{
     .{ .cpu_arch = .aarch64, .os_tag = .macos, .abi = null },
     .{ .cpu_arch = .x86_64, .os_tag = .macos, .abi = null },
     .{ .cpu_arch = .aarch64, .os_tag = .linux, .abi = .musl },
     .{ .cpu_arch = .x86_64, .os_tag = .linux, .abi = .musl },
 };
 
+const supported_targets: []const std.Target.Query = &(main_targets ++ .{
+    .{ .cpu_arch = .aarch64, .os_tag = .linux, .abi = .gnu },
+    .{ .cpu_arch = .x86_64, .os_tag = .linux, .abi = .gnu },
+});
+
+const targets: []const std.Target.Query = &main_targets;
+
 const BuildCfg = struct {
     version: []const u8,
     pace: []const u8,
@@ -22,7 +29,7 @@ const BuildCfg = struct {
 };
 
 pub fn build(b: *std.Build) !void {
-    const target = b.standardTargetOptions(.{ .whitelist = targets });
+    const target = b.standardTargetOptions(.{ .whitelist = supported_targets });
     var optimize = b.standardOptimizeOption(.{});
 
     //

ext/avahi/build.zig

@@ -538,7 +538,8 @@ pub fn build(b: *std.Build) void {
     avahi.root_module.addCMacro("HAVE_DBUS_CONNECTION_CLOSE", "0");
     avahi.root_module.addCMacro("HAVE_EXPAT_H", "1");
     avahi.root_module.addCMacro("HAVE_CONFIG_H", "1");
-    avahi.root_module.addCMacro("HAVE_STRLCPY", "1");
+    if (!t.isGnu())
+        avahi.root_module.addCMacro("HAVE_STRLCPY", "1");
 
     const avahi_config_h = b.addConfigHeader(.{
         .style = .blank,

ext/h2o/build.zig

@@ -55,6 +55,10 @@ pub fn build(b: *std.Build) !void {
         .files = &.{"cloexec.c"},
         .flags = &.{
             "-fno-sanitize=all",
+            if (t.isGnu())
+                "-D_GNU_SOURCE"
+            else
+                "",
         },
     });