This commit: https://gitlab.com/freepascal.org/fpc/source/-/commit/ee10850a5793b69b19dc82b9c28342bdd0018f2e Its causing string memory leaks on Linux AArch64. I have not checked other Arch's. To test: program project1; var s:string; begin SetLength(S,100); end. The above program leaks 117 bytes on Linux AArch64. If a previous commit (parent) is used for compilation (https://gitlab.com/freepascal.org/fpc/source/-/commit/ea6529ff63225e13baa4e1fd2c193b84d1432048) no leaks occur. Additional info. Lazarus trunk crashes due to out-of-memory errors when latest FPC trunk is used within a couple of minutes. Lazarus trunk runs perfect with low memory consumption when the parent of the offending FPC commit is used.