Oolite Bulletins

I was able to get Oolite to build with Clang.

To force Clang usage, in the shell I did:

export CC=/usr/bin/clang
export CXX=/usr/bin/clang++


I built libobjc2 2.2.1 from source as described here in that shell.

I built gnustep-base-1.31.1 from source as described here in the same shell (to ensure I still have the 2 exports to force Clang usage).


Then I built Oolite which compiled and linked fine. It ran and opened its window with Oolite logo, but then crashed with:

Configuration contains unknown keys - ("GNUSTEP_FILESYSTEM_LAYOUT")
Add them in the comma separated list GNUSTEP_EXTRA=... if required.
2025-07-22 19:58:06.426 oolite[37078:37079] Truncating thread name 'OOLogOutputHandler logging thread' to 15 characters due to platform limitations
oolite: /home/mcarans/Code/libobjc2-2.2.1/protocol.h:85: struct objc_protocol_method_description *protocol_method_at_index(struct objc_protocol_method_description_list *, int): Assertion `l->size >= sizeof(struct objc_protocol_method_description)' failed.
Aborted (core dumped)

Does anyone know what might be causing this error?

I had to add to the GNUmakefile above the line OBJC_PROGRAM_NAME = oolite:

ADDITIONAL_OBJCFLAGS += -fobjc-runtime=gnustep-1.9


Then Oolite starts up ok after clean and build. Adding ADDITIONAL_LDFLAGS += -fuse-ld=lld to force the use of the Clang/LLVM linker ldd instead of GNU's ld gives a segmentation fault for me. That means that rather strangely, I must use GNU's linker ld for linking when compiling with Clang (and gcc).

The -fobjc-runtime flag is described as follows here:

The GNUstep Objective-C runtime was designed as a drop-in replacement for the GCC runtime. It supports three ABIs:

• The old GCC ABI, which provides support for Objective-C 1.0 features. This can be selected via the -fobjc-runtime=gcc flag in Clang or by compiling with GCC.
• The initial GNUstep non-fragile ABI, which was intended to be compatible with the GCC ABI, but provide support for modern Objective-C features. This can be selected with the -fobjc-runtime=gnustep-1.9 flag in Clang.
• The modern (v2) ABI, which provides richer reflection metadata, smaller binaries and reduced memory usage. This is selected with the -fobjc-runtime=gnustep-2.0 flag in Clang 7.0 or later.

I've documented this in the wiki: https://wiki.alioth.net/index.php/Compi ... ead_of_gcc (it is linked to from the Developer's Corner page).

I played the Oolite build compiled with Clang and it worked without any issues. I could not see any difference compared to compiling with gcc when playing the game.

The Clang flag is now in the GNUmakefile and so doesn't need to be added manually when building Oolite with Clang instead of gcc.