`make check` creates files example{1,2,3}.dot

[lilyball]

It looks like the doc tests for libgraphviz create files example{1,2,3}.dot, which end up being left behind in the cwd after running make check.

I'm not sure what the correct solution here is. The doc tests could explicitly try to write to /tmp, but it may make more sense for rustdoc's test runner to use a temporary directory as the cwd so the individual tests don't have to worry about this.

[pnkfelix]

cc me

[pnkfelix]

a simpler short-term solution could be to avoid generating the files in the first place.

• Easiest way to do that: Add either ignore or preferably no_run to the code blocks.
• Slightly harder (but better for testing): refactor the code so that the graphviz testing parts are parameterized over their Writer. Add a hidden code block that runs those with an in-memory writer. Then add a shown but ignore'd code block that just contains a very short main that calls out to the functions from the earlier block.