From 4ae67ebf1b7027cf33ecd96317d745ccf54987fb Mon Sep 17 00:00:00 2001
From: Manlio Perillo <manlio.perillo@gmail.com>
Date: Sun, 7 May 2023 20:01:02 +0200
Subject: [PATCH] build: don't install skipped exercises

Update the code in `zig build install` and `zig build -Dn=n install`, so
that exercises that must be skipped are not installed, since it will
cause an error.  Ensure that a skip message is printed.
---
 build.zig | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/build.zig b/build.zig
index 68f43eb..e6f2688 100644
--- a/build.zig
+++ b/build.zig
@@ -133,17 +133,20 @@ pub fn build(b: *Build) !void {
             print("unknown exercise number: {}\n", .{n});
             std.os.exit(1);
         }
-
         const ex = exercises[n - 1];
 
         const build_step = ex.addExecutable(b, work_path);
-        b.installArtifact(build_step);
+
+        const skip_step = SkipStep.create(b, ex);
+        if (!ex.skip)
+            b.installArtifact(build_step)
+        else
+            b.getInstallStep().dependOn(&skip_step.step);
 
         const run_step = b.addRunArtifact(build_step);
 
         const test_step = b.step("test", b.fmt("Run {s} without checking output", .{ex.main_file}));
         if (ex.skip) {
-            const skip_step = SkipStep.create(b, ex);
             test_step.dependOn(&skip_step.step);
         } else {
             test_step.dependOn(&run_step.step);
@@ -201,7 +204,12 @@ pub fn build(b: *Build) !void {
     var prev_step = &header_step.step;
     for (exercises) |ex| {
         const build_step = ex.addExecutable(b, work_path);
-        b.installArtifact(build_step);
+
+        const skip_step = SkipStep.create(b, ex);
+        if (!ex.skip)
+            b.installArtifact(build_step)
+        else
+            b.getInstallStep().dependOn(&skip_step.step);
 
         const verify_stepn = ZiglingStep.create(b, ex, work_path);
         verify_stepn.step.dependOn(prev_step);