Working on a codebase however is not what the license says. It says specifically "making modifications".
If you have the Perl script that generates C code, you get a benefit from being able to modify the Perl script rather than the C code. So the Perl script is the preferred form for making modifications.
If you have the history, you don't get any benefit from modifying the history. In this sense, having the history is not relevant to making modifications, only to studying the code (for example to make the same modifications on another branch/fork of the code, like I do with upstream patches, or like Oracle could do if they had the Red Hat patches).
Your could say that this phrasing is shortsighted, but note that neither Red Hat not Debian or anyone else has ever given the complete history to Linux or any other piece of software they distribute, but they had to give the complete base source tarball as distributed by the upstream project.
> In this sense, having the history is not relevant to making modifications, only to studying the code
Studying the code is the first step in making modifications. I would always want to have a working "git blame" before trying to modify a codebase, so that I could understand lines in the context of the changes they were part of before I modified those lines. I consider it considerably harder to modify a codebase when I don't have proper version control history available.
If you have the Perl script that generates C code, you get a benefit from being able to modify the Perl script rather than the C code. So the Perl script is the preferred form for making modifications.
If you have the history, you don't get any benefit from modifying the history. In this sense, having the history is not relevant to making modifications, only to studying the code (for example to make the same modifications on another branch/fork of the code, like I do with upstream patches, or like Oracle could do if they had the Red Hat patches).
Your could say that this phrasing is shortsighted, but note that neither Red Hat not Debian or anyone else has ever given the complete history to Linux or any other piece of software they distribute, but they had to give the complete base source tarball as distributed by the upstream project.