Provide some BuildInfo even for non-CI builds.

Ref.: #2204

CMakeLists.txt

@@ -24,6 +24,7 @@ if(DEFINED ENV{TRAVIS_BUILD_WITH_COVERAGE})
 endif()
 
 if(DEFINED ENV{MCSERVER_BUILD_ID})
+	# The build info is defined by the build system (Travis / Jenkins)
 	set(BUILD_ID $ENV{MCSERVER_BUILD_ID})
 	set(BUILD_SERIES_NAME $ENV{MCSERVER_BUILD_SERIES_NAME})
 	set(BUILD_DATETIME $ENV{MCSERVER_BUILD_DATETIME})
@@ -34,12 +35,34 @@ if(DEFINED ENV{MCSERVER_BUILD_ID})
 		execute_process(
 			COMMAND git rev-parse HEAD
 			RESULT_VARIABLE GIT_EXECUTED
-			OUTPUT_VARIABLE BUILD_COMMIT_ID)
-			string(STRIP ${BUILD_COMMIT_ID} BUILD_COMMIT_ID)
+			OUTPUT_VARIABLE BUILD_COMMIT_ID
+		)
+		string(STRIP ${BUILD_COMMIT_ID} BUILD_COMMIT_ID)
 		if (NOT (GIT_EXECUTED EQUAL 0))
 			message(FATAL_ERROR "Could not identifiy git commit id")
 		endif()
 	endif()
+else()
+	# This is a local build, stuff in some basic info:
+	set(BUILD_ID "Unknown")
+	set(BUILD_SERIES_NAME "local build")
+	execute_process(
+		COMMAND git rev-parse HEAD
+		RESULT_VARIABLE GIT_EXECUTED
+		OUTPUT_VARIABLE BUILD_COMMIT_ID
+	)
+	string(STRIP ${BUILD_COMMIT_ID} BUILD_COMMIT_ID)
+	execute_process(
+		COMMAND git log -1 --date=iso --pretty=format:%ai
+		OUTPUT_VARIABLE BUILD_DATETIME
+	)
+	string(STRIP ${BUILD_DATETIME} BUILD_DATETIME)
+
+	# The BUILD_COMMIT_ID and BUILD_DATETIME aren't updated on each repo pull
+	# They are only updated when cmake re-configures the project
+	# Therefore mark them as "approx: "
+	set(BUILD_COMMIT_ID "approx: ${BUILD_COMMIT_ID}")
+	set(BUILD_DATETIME "approx: ${BUILD_DATETIME}")
 endif()
 
 # We need C++11 features, Visual Studio has those from VS2012, but it needs a new platform toolset for those; VS2013 supports them natively:

src/CMakeLists.txt

@@ -83,6 +83,7 @@ SET (HDRS
 	BlockTracer.h
 	Broadcaster.h
 	BoundingBox.h
+	BuildInfo.h
 	BuildInfo.h.cmake
 	ByteBuffer.h
 	ChatColor.h