There were a lot of instances of this lint error
printf: non-constant format string in call to github.com/rclone/rclone/fs.Logf (govet)
Which were fixed by re-arranging the arguments and adding "%s".
There were quite a few genuine bugs which were found too.
golang.org/x/oauth2/jws is deprecated: this package is not intended for public use and
might be removed in the future. It exists for internal use only. Please switch to another
JWS package or copy this package into your own source tree.
github.com/golang-jwt/jwt/v4 seems to be a good alternative, and was already
an implicit dependency.
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.
This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.