Add some more information to verbose version.

[ehuss]

This adds a little bit of extra information to the verbose version command.

cc #6275 and #6161

Some examples of what it might look like:

cargo 1.57.0
release: 1.57.0
host: x86_64-unknown-linux-gnu
libgit2: 1.3.0 (sys:0.13.23 vendored)
libcurl: 7.79.1-DEV (sys:0.4.49+curl-7.79.1 vendored ssl:OpenSSL/1.1.1k)
ssl: OpenSSL 1.1.1k  25 Mar 2021

cargo 1.57.0
release: 1.57.0
host: x86_64-pc-windows-msvc
libgit2: 1.3.0 (sys:0.13.23 vendored)
libcurl: 7.79.1-DEV (sys:0.4.49+curl-7.79.1 vendored ssl:Schannel)

cargo 1.57.0
release: 1.57.0
host: x86_64-apple-darwin
libgit2: 1.3.0 (sys:0.13.23 vendored)
libcurl: 7.64.1 (sys:0.4.49+curl-7.79.1 system ssl:(SecureTransport) LibreSSL/2.8.3)
ssl: OpenSSL 1.1.1l  24 Aug 2021

[rust-highfive]

r? @Eh2406

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[ehuss]

This doesn't include everything mentioned in #6275 and #6161. Things not included:

• Doesn't include git hashes for various libraries. I think the version information provided should be sufficient, and that information is generally not available.
• Doesn't explicitly call out SChannel/SecureTransport, however libcurl shows that for us, and I think that's all that really matters.
• libgit2 doesn't expose information about which ssl library it is using.
• libssh2: didn't include anything, it is not currently exposed. Also, issue reports around ssh2 are extremely rare, so this didn't seem too interesting to me.
• zlib: This is not exposed, and not too interesting to me.
• default target: I'm not sure what this means (the build.target config value?). I didn't think this was too interesting.
• current crates.io index version: This isn't particularly interesting to me, since I don't recall ever seeing any issues posted that needed to use an older index.

I'm not saying the above information isn't useful, I just don't want to spend a lot of time on this.

The only thing missing that I really want is the OS version. However, that is extremely difficult to get reliably. I found https://crates.io/crates/os_info which actually looks to be pretty thorough and well written for the few platforms that I looked at. However, I don't know if that covers every platform we build for, and I fear it will make life difficult for people porting cargo to other platforms. Thoughts?

[alexcrichton]

For OS version information are you thinking of learning about things like the macOS patch number or things like that? I find it doesn't come up too too often but I agree that if it's easy-ish to put in here then we may as well because it can often be a red flag if something is super old or extremely new.

I'm not too worried about the platform compatibility in that if we know about it ahead of time we can have it be opt-in for platforms instead of opt-out. For example we could probably turn it on for macOS and Windows by default and then allow-list platforms like Linux and such as they are implemented. If something is missing from a platform's cargo -vV then we still have the host target that Cargo was built for which helps at least a little bit.

Otherwise though this looks great to me and r=me when you feel like this is ready.

[Eh2406]

Thank you for moving this forward!

I have had cases where resolver bugs did not reproduce that we thought where do to index changes. But now I cant find a link to an example. So it can't be that common.

os_info looks pretty useful, may as well use it.

Anyway +1 from me when you are happy!

[ehuss]

OK, I went ahead and added os_info. It looks like it has a fallback for all unknown platforms. If it causes problems, we can figure out what to do from there.

@bors r=alexcrichton,Eh2406

[bors]

📌 Commit 9f5da7c has been approved by alexcrichton,Eh2406

[bors]

⌛ Testing commit 9f5da7c with merge c7957a7...

[bors]

☀️ Test successful - checks-actions
Approved by: alexcrichton,Eh2406
Pushing c7957a7 to master...