Worked on the zephyrproject-rtos/zephyr repository to address a critical bug affecting toolchain configuration consistency and build reliability. Focused on aligning toolchain settings with the C18 standard by updating configuration references and employing a generic matcher for C language versions. This approach reduced discrepancies between C99 and C18 standards, ensuring more predictable builds across different toolchains. The work involved C programming, compiler design, and toolchain configuration, with changes specifically targeting the file_tag matcher to correct variable usage. By resolving this bug, the developer contributed to a more stable and consistent build process, enhancing the overall reliability of the Zephyr project.