Hi Amit, This issue was fixed in this commit: https://github.com/seL4/camkes-tool/commit/3ea3061f066051a7a099cabed140163d5... You can upgrade to the current version of the tutorials with repo init -u https://github.com/SEL4PROJ/sel4-tutorials-manifest instead of repo init -u https://github.com/SEL4PROJ/sel4-tutorials-manifest -b refs/tags/10.0.0 which should fix your problem. Alternatively, you could force the definition of CAMKES_C_FMT_INVOCATION in camkes.cmake to "" which will stop the code formatting commands from being generated. Kind regards, Kent ________________________________________ From: Devel on behalf of Amit Goyal Sent: Wednesday, September 5, 2018 1:10 AM To: devel@sel4.systems Subject: [seL4] Camkes Build Error Hi All, My Camkes has been working fine since now. Suddenly, it stopped working and produce the attached error log on running ninja. I am running it on x86 system (i5 processor), ubuntu 16.04 on qemu: I am running the following commands: mkdir build cd build ../init --plat pc99 --tut hello-camkes-2 --solution ninja Can you please suggest a possible way out? -- Thanks and Regards, Amit Goyal