Show the package name for which the error associated

In certain cases, it's unclear which package causes an error during shard installation.
These changes improves error messages by adding explicit package context.
When an error occurs, the log will now indicate which package triggered the failure.

Author: miry

spec/integration/install_spec.cr

@@ -855,7 +855,7 @@ describe "install" do
     with_shard(metadata) do
       ex = expect_raises(FailedCommand) { run "shards install --no-color" }
       ex.stdout.should contain <<-ERROR
-        E: Could not find executable "nonexistent"
+        E: Failed to install `executable_missing`: Could not find executable "nonexistent"
         ERROR
     end
   end

src/cli.cr

@@ -176,12 +176,19 @@ end
 begin
   Shards.run
 rescue ex : OptionParser::InvalidOption
-  Shards::Log.fatal { ex.message }
+  Shards::Log.fatal(exception: ex) { ex.message }
+  Shards::Log.trace { ex.inspect_with_backtrace }
   exit 1
 rescue ex : Shards::ParseError
   ex.to_s(STDERR)
   exit 1
+rescue ex : Shards::Package::Error
+  package = ex.package
+  Shards::Log.error(exception: ex) { "Failed to install `#{package.name}`: #{ex.message}" }
+  Shards::Log.trace { ex.inspect_with_backtrace }
+  exit 1
 rescue ex : Shards::Error
-  Shards::Log.error { ex.message }
+  Shards::Log.error(exception: ex) { ex.message }
+  Shards::Log.trace { ex.inspect_with_backtrace }
   exit 1
 end

src/package.cr

@@ -3,6 +3,14 @@ require "./helpers"
 
 module Shards
   class Package
+    class Error < Shards::Error
+      getter package
+
+      def initialize(message, @package : Package)
+        super message
+      end
+    end
+
     getter name : String
     getter resolver : Resolver
     getter version : Version
@@ -114,7 +122,7 @@ module Shards
       spec.executables.each do |name|
         exe_name = find_executable_file(Path[install_path], name)
         unless exe_name
-          raise Shards::Error.new("Could not find executable #{name.inspect}")
+          raise Shards::Package::Error.new("Could not find executable #{name.inspect}", package: self)
         end
         Log.debug { "Install #{exe_name}" }
         source = File.join(install_path, exe_name)