Improve error message on home directory mismatch

[calebcartwright]

Refs #1884 - Augment error message displayed to the user when there's a mismatch between $HOME and the euid-obtained value for the home directory

[calebcartwright]

AppVeyor had a couple tests failing, all with an error message of: An attempt was made to create more links on a file than the file system supports.

I don't think that's due to the changes here (I see the same error message in other PR builds), but let me know if that's something I need to look at on my end.

[kinnison]

AppVeyor had a couple tests failing, all with an error message of: An attempt was made to create more links on a file than the file system supports.

I don't think that's due to the changes here (I see the same error message in other PR builds), but let me know if that's something I need to look at on my end.

Yeah, that's appveyor being a pain. I'm looking at what it might take to switch to a different Windows provider for builds. I'm going to chat to someone from Travis tomorrow.

[kinnison]

I think this looks good to me.

Noticed a problem

[kinnison]

Please fold the commits together - 'chore' commits are not in-style for rustup.

Once that's done it looks good to me.

[calebcartwright]

thanks @kinnison! squashed accordingly.

so I know for future reference, is it that rustup uses different commit message standards or that contributors should squash all commits into one?

[calebcartwright]

Travis failure seems unrelated, but again please let me know if there's anything needed on my end

info: downloading component 'rustfmt'
error: component download failed for rustfmt-x86_64-unknown-linux-gnu
info: caused by: could not download file from 'https://static.rust-lang.org/dist/2019-05-23/rustfmt-1.2.0-x86_64-unknown-linux-gnu.tar.xz' to '/home/travis/.rustup/downloads/c6a734a2721ec288f9e96d7e33f23fd1ed6f85effd4bcac28f020f7b2db247fb.partial'
info: caused by: failed to make network request
info: caused by: https://static.rust-lang.org/dist/2019-05-23/rustfmt-1.2.0-x86_64-unknown-linux-gnu.tar.xz: timed out
error: 'rustfmt' is not installed for the toolchain 'stable-x86_64-unknown-linux-gnu'

[kinnison]

thanks @kinnison! squashed accordingly.

so I know for future reference, is it that rustup uses different commit message standards or that contributors should squash all commits into one?

It's more that I prefer the commits be actually useful for working out why a line is what it is.

i.e. the change should be attributed to the functional difference, not that you were making a cleanup in response to a code review :D

[kinnison]

Travis failure seems unrelated, but again please let me know if there's anything needed on my end

I've retried the travis, it shouldn't be anything you did, looks like an internal timeout in Travis