From a7b962c11aedec523cf6739cfb07958214fbc7fb Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Fri, 8 Sep 2023 21:04:28 -0400
Subject: [PATCH] Output a better error when pkg-config is not found - close
 #169

---
 build_tests/configure/check_cfg_no_pkg_config.rb | 5 +++++
 lib/rscons/configure_op.rb                       | 7 ++++++-
 spec/build_tests_spec.rb                         | 7 +++++++
 3 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 build_tests/configure/check_cfg_no_pkg_config.rb

diff --git a/build_tests/configure/check_cfg_no_pkg_config.rb b/build_tests/configure/check_cfg_no_pkg_config.rb
new file mode 100644
index 0000000..e0de024
--- /dev/null
+++ b/build_tests/configure/check_cfg_no_pkg_config.rb
@@ -0,0 +1,5 @@
+ENV["PATH"] = ""
+
+configure do
+  check_cfg package: "mypackage"
+end
diff --git a/lib/rscons/configure_op.rb b/lib/rscons/configure_op.rb
index 9d3e7b4..5bab789 100644
--- a/lib/rscons/configure_op.rb
+++ b/lib/rscons/configure_op.rb
@@ -125,7 +125,12 @@ module Rscons
       elsif program = options[:program]
         Ansi.write($stdout, "Checking '", :cyan, program, :reset, "'... ")
       end
-      program ||= "pkg-config"
+      unless program
+        program = "pkg-config"
+        unless Util.find_executable(program)
+          raise RsconsError.new("Error: executable '#{program}' not found")
+        end
+      end
       args = options[:args] || %w[--cflags --libs]
       command = [program, *args, package].compact
       stdout, _, status = log_and_test_command(command)
diff --git a/spec/build_tests_spec.rb b/spec/build_tests_spec.rb
index b321de3..2f5ec41 100644
--- a/spec/build_tests_spec.rb
+++ b/spec/build_tests_spec.rb
@@ -2369,6 +2369,13 @@ EOF
           expect(result.stdout).to_not match /gcc.*-o.*myconfigtest1.*-DMYPACKAGE/
           expect(result.stdout).to match /gcc.*-o.*myconfigtest2.*-DMYPACKAGE/
         end
+
+        it "indicates that pkg-config command cannot be found" do
+          test_dir "configure"
+          result = run_rscons(args: %w[-f check_cfg_no_pkg_config.rb configure])
+          expect(result.stderr).to match /Error: executable 'pkg-config' not found/
+          expect(result.status).to_not eq 0
+        end
       end
 
       context "when passed a program" do