"mdbook test" fails immediately: No such file or directory

[RalfJung]

I installed mdbook and then ran mdbook test as described in the README, but all that does is

2018-07-16 13:03:07 [ERROR] (mdbook::utils): Error: Unable to open the file
2018-07-16 13:03:07 [ERROR] (mdbook::utils): 	Caused By: No such file or directory (os error 2)

[RalfJung]

Judging from the strace output, it seems confused by the lack of an index.md?

[RalfJung]

mdBook 0.1.8 got released the day CI started failing, so I guess that's what broke it.

Cc @Michael-F-Bryan

[RalfJung]

This actually seems to be a bug in mdBook because the update claims to be semver-compatible, but as this examples shows, it is not.

[Gankra]

cc @steveklabnik

[Lokathor]

As of v0.2.3 or later this seems to be fixed. I was able to mdbook build and then mdbook test.

We can probably close this one.