> I'm not sure when you see that error (is it when loading the package or
when installing it?).
Loading, yes!
> Assuming it's when loading it, could it be that
you're loading the package in a version of Emacs noticeably older than
the one that compiled the files?
No, it's the exact same binary that installed the package as the one running it. But if I look at the byte code, the one that package.el produced is not the same as if I would run byte-compile-file.
> The elpa package is supposed to come without any .elc files, and the .el
files are supposed to be byte-compiled during installation. Did this
work correctly?
I can see no errors or warnings. See attached log file.