`with_clean_env` has been deprecated in `with_unbundled_env`. It already generates a deprecation warning when it uses, but this man page was still referring to it.
Previously they had slightly different behavior when combined with
conservative updating flags.
The correct behavior is the `--update-strict` option, so `--script` now
does that, The `--update-strict` option is left there for now but I will
deprecate it later.
ab42046229
Very often github source is used to temporarily use a modified gem
while a PR upstream is being reviewed.
So for instance https://github.com/ruby/bigdecimal/pull/211 will look like:
```ruby
gem "bigdecimal", github: "casperisfine/bigdecimal", branch: "git-gem" # https://github.com/ruby/bigdecimal/pull/200
```
It's annoying because you have to fiddle with the branch name, which is copied as `casperisfine:git-gem`, etc etc.
If I could simply use the PR URL like this:
```
gem "bigdecimal", github: "https://github.com/ruby/bigdecimal/pull/211"
```
It would make a very common task for me so much simpler.
517c527751
