fixed bad regex checks for optional groups

src/tasks/boost.cpp

@@ -168,9 +168,9 @@ void boost::write_config_jam()
 	oss
 		<< "using python\n"
 		<< "  : " << python_version_for_jam() << "\n"
-		<< "  : " << python::python_exe().generic_string() << "\n"
-		<< "  : " << python::include_path().generic_string() << "\n"
-		<< "  : " << python::build_path().generic_string() << "\n"
+		<< "  : " << path_to_utf8(python::python_exe()) << "\n"
+		<< "  : " << path_to_utf8(python::include_path()) << "\n"
+		<< "  : " << path_to_utf8(python::build_path()) << "\n"
 		<< "  : <address-model>64\n"
 		<< "  : <define>BOOST_ALL_NO_LIB=1\n"
 		<< "  ;";
@@ -281,7 +281,7 @@ std::string boost::boost_version_no_tags()
 	// 1.72.1
 	std::string s = m[1].str() + "." + m[2].str();
 
-	if (m.size() > 3)
+	if (m[3] != "")
 		s += "." + m[3].str();
 
 	return s;
@@ -299,13 +299,13 @@ std::string boost::boost_version_all_underscores()
 	// boost_1_72_0_b1_rc1
 	std::string s = "boost_" + m[1].str() + "_" + m[2].str();
 
-	if (m.size() > 3)
+	if (m[3] != "")
 		s += "_" + m[3].str();
 
-	if (m.size() > 4)
+	if (m[4] != "")
 		s += "_" + m[4].str();
 
-	if (m.size() > 5)
+	if (m[5] != "")
 		s += "_" + m[5].str();
 
 	return s;

src/tasks/openssl.cpp

@@ -235,7 +235,7 @@ std::string openssl::version_no_minor_underscores()
 {
 	auto m = parse_version();
 
-	if (m.size() == 2)
+	if (m[2] == "")
 		return m[1].str();
 	else
 		return m[1].str() + "_" + m[2].str();

src/tasks/python.cpp

@@ -33,9 +33,7 @@ python::version_info python::parsed_version()
 
 	v.major = m[1];
 	v.minor = m[2];
-
-	if (m.size() > 3)
-		v.patch = m[3];
+	v.patch = m[3];
 
 	return v;
 }

src/tasks/task.cpp

@@ -232,7 +232,7 @@ void task::threaded_run(std::string thread_name, std::function<void ()> f)
 	}
 	catch(std::exception& e)
 	{
-		error("{} uncaught exception: {}", name(), e.what());
+		error("uncaught exception in task {}: {}", name(), e.what());
 		interrupt_all();
 	}
 }