📦️ Allow packaging when cert file present

Author: pboling

version_gem.gemspec

@@ -13,11 +13,15 @@ Gem::Specification.new do |spec|
   # Ref: https://gitlab.com/oauth-xx/version_gem/-/issues/3
   # Hence, only enable signing if the cert_file is present.
   cert_file = ENV.fetch("GEM_CERT_PATH", "certs/#{ENV.fetch("GEM_CERT_USER", ENV["USER"])}.pem")
-  if cert_file && File.exist?(cert_file)
+  if cert_file && File.exist?(File.join(__dir__, cert_file))
     spec.cert_chain = [ENV.fetch("GEM_CERT_PATH", "certs/#{ENV.fetch("GEM_CERT_USER", ENV["USER"])}.pem")]
-    if $PROGRAM_NAME.end_with?("gem") && ARGV == ["build", __FILE__]
+    if $PROGRAM_NAME.end_with?("gem", "rake") && ARGV[0] == "build"
       spec.signing_key = File.expand_path("~/.ssh/gem-private_key.pem")
+    else
+      warn "Packaging via #{$PROGRAM_NAME} with #{ARGV.inspect}"
     end
+  else
+    warn "No Cert File Found. May package without signing."
   end
 
   spec.name = "version_gem"