Failure to reproduce the compilation locally: app is refused on the nwa flashing website

[Naereen]

When trying to reproduce the compilation of this app, I get no error when calling make build, but then the app fails to be accepted on the nwa flashing website for Numworks.
On that page, the Chrome dev tools show this error:

apps:1 Uncaught (in promise) ./this.program: app.nwa: in function `__libc_fini_array':
/build/newlib-pB30de/newlib-3.3.0/build/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/libc/misc/../../../../../../../../newlib/libc/misc/fini.c:36: undefined reference to `_fini'
./this.program: app.nwa: in function `_sbrk':
/build/newlib-pB30de/newlib-3.3.0/build/arm-none-eabi/thumb/v7e-m+fp/hard/libgloss/libnosys/../../../../../../../libgloss/libnosys/sbrk.c:21: undefined reference to `end'

Installing the application provided here on your GitHub release page (or on https://yaya-cout.github.io/Nwagyu/guide/apps/lua.html) works fine.

Do you have any idea why my local build fails to be accepted by the nwa flashing website?
Thanks in advance! Regards, @Naereen

[Naereen]

Also: The size of the app is shown as "Size: NaN KB" on the flashing website.

[Naereen]

Note: I encounter the exact same issue if I run make run locally with my Numworks calculator connected.