Rename libmain.adb to ahven_libmain.adb. As someone might use multiple libraries, which all might have their own libmain.adb, rename libmain.adb to ahven_libmain.adb. This way our main file, which lists the dependencies for the library, is more or less unique and doesn't conflict with other libmain.adb files.
Add SPDX license identifiers to source code. To help the automatic scanners to identify the license of the source code, add SPDX license identifiers as specified at https://spdx.github.io/spdx-spec/appendix-V-using-SPDX-short-identifiers-in-source-files/ In our case, the line is: SPDX-License-Identifier: ISC for every file.