Issue building with Alire

[Nibroc6]

When trying to build and run the words program with Alire, as per this guide, the compiler (at least I think that's what it is; I'm pretty new to compiled languages, and this is my first time working with ada) throws the following error:

...[a bunch of stuff that looks fine up here]...
   [Ada]          latin_utils-dictionary_package.adb
   [Ada]          latin_utils-config.ads
   [Ada]          support_utils.ads
   [Ada]          support_utils-word_support_package.adb
   [Ada]          support_utils-word_parameters.adb
   [Ada]          support_utils-uniques_package.ads
cannot generate code for file latin_utils-config.ads (package spec)

   compilation of latin_utils-config.ads failed

gprbuild: *** compilation phase failed
ERROR: Command ["gprbuild", "-s", "-j0", "-p", "-P", "C:\Users\<my user name>\Desktop\whitakers-words\commands.gpr"] exited with code 4
ERROR: Compilation failed.

If anyone would be willing to let me know what I'm doing wrong, that would be really great.

Thanks!