Update cc, git2, num_cpus.

[ehuss]

This updates the cc crate, bringing in better parallel building support. Also updates git2 which enables the parallel feature. (Note: I don't expect it will have a significant impact on build time, but seems good to update anyways.)

The main thorn is that cc gained knowledge about RISC-V architectures (rust-lang/cc-rs#428, rust-lang/cc-rs#429, rust-lang/cc-rs#430), but the builders on CI do not have the riscv C compiler installed. This means that bootstraps' cc detection was finding a C compiler that isn't installed, and fails.

The solution here is to override the cc detection to false. The C compiler isn't actually used on riscv platforms. AFAIK, the only location would be compiler_builtins, and it currently forces C support off (https://github.com/rust-lang/compiler-builtins/blob/a533ae9c5aa325db209659679535fe1f186eae81/build.rs#L49-L55).

Other possible solutions:

• Add the override in cc_detect for riscv (or any "no-C" platform like wasm32 and nvptx)
• Install and use the appropriate c compiler. I tried this the g++-riscv64-linux-gnu package, but it failed missing some header file.

Closes #66232

[rust-highfive]

r? @alexcrichton

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[ehuss]

@bors rollup=never
I've tested this locally for riscv, but I'm not confident everything will work.

[alexcrichton]

@bors: r+

[bors]

📌 Commit a902383 has been approved by alexcrichton

[bors]

⌛ Testing commit a902383 with merge 9a9d603a70ce6fb0467d622e1b52fc43ad2e0189...

[bors]

💥 Test timed out

[ehuss]

@bors retry
I'm a bit confused, as it looks like bors merged it to the auto branch, but the azure build never started? At least, I can't find any indication on the pipeline history page.

[bors]

⌛ Testing commit a902383 with merge dcc9a8b94e1de34869825f9be69be6c716cb3806...

[rust-highfive]

Your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

2019-11-15T23:08:33.9685007Z 
2019-11-15T23:08:33.9685055Z 
2019-11-15T23:08:33.9685085Z 
2019-11-15T23:08:33.9685113Z 
2019-11-15T23:08:33.9685246Z - Add the override in cc_detect for riscv (or any "no-C" platform like wasm32 and nvptx)
2019-11-15T23:08:33.9685770Z - Install and use the appropriate c compiler. I tried this the `g++-riscv64-linux-gnu` package, but it failed missing some header file.
2019-11-15T23:08:33.9686054Z AGENT_DISABLELOGPLUGIN_TESTFILEPUBLISHERPLUGIN=true
2019-11-15T23:08:33.9686139Z AGENT_DISABLELOGPLUGIN_TESTRESULTLOGPLUGIN=true
2019-11-15T23:08:33.9686244Z AGENT_HOMEDIRECTORY=C:\agents\2.160.1
2019-11-15T23:08:33.9686316Z AGENT_ID=514
---
2019-11-15T23:08:33.9713345Z TMP=/tmp
2019-11-15T23:08:33.9713413Z TOOLSTATE_ISSUES_API_URL=https://api.github.com/repos/rust-lang/rust/issues
2019-11-15T23:08:33.9713522Z TOOLSTATE_PUBLISH=1
2019-11-15T23:08:33.9713638Z TOOLSTATE_REPO=https://github.com/rust-lang-nursery/rust-toolstate
2019-11-15T23:08:33.9713868Z The main thorn is that `cc` gained knowledge about RISC-V architectures (https://github.com/alexcrichton/cc-rs/pull/428, https://github.com/alexcrichton/cc-rs/pull/429, https://github.com/alexcrichton/cc-rs/pull/430), but the builders on CI do not have the riscv C compiler installed. This means that bootstraps' cc detection was finding a C compiler that isn't installed, and fails.
2019-11-15T23:08:33.9714158Z The solution here is to override the cc detection to `false`. The C compiler isn't actually used on riscv platforms. AFAIK, the only location would be compiler_builtins, and it currently forces C support off (https://github.com/rust-lang/compiler-builtins/blob/a533ae9c5aa325db209659679535fe1f186eae81/build.rs#L49-L55).
2019-11-15T23:08:33.9714413Z This updates the `cc` crate, bringing in better parallel building support. Also updates `git2` which enables the parallel feature. (Note: I don't expect it will have a significant impact on build time, but seems good to update anyways.)
2019-11-15T23:08:33.9724118Z USERDOMAIN=fv-az379
2019-11-15T23:08:33.9724197Z USERDOMAIN_ROAMINGPROFILE=fv-az379
2019-11-15T23:08:33.9724287Z USERNAME=VssAdministrator
2019-11-15T23:08:33.9724350Z USERPROFILE=C:\Users\VssAdministrator
2019-11-15T23:08:33.9724350Z USERPROFILE=C:\Users\VssAdministrator
2019-11-15T23:08:33.9724427Z Update cc, git2, num_cpus.
2019-11-15T23:08:33.9724582Z VS140COMNTOOLS=C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Tools\
2019-11-15T23:08:33.9724655Z VSTS_AGENT_PERFLOG=c:\vsts\perflog
2019-11-15T23:08:33.9724747Z VSTS_PROCESS_LOOKUP_ID=vsts_23d78c07-fce6-46fc-835f-3b1040ac804e
2019-11-15T23:08:33.9724831Z WINDIR=C:\windows
---
2019-11-15T23:11:45.2850045Z Chocolatey installed 0/1 packages. 1 packages failed.
2019-11-15T23:11:45.2850505Z  See the log for details (C:\ProgramData\chocolatey\logs\chocolatey.log).
2019-11-15T23:11:45.2855201Z 
2019-11-15T23:11:45.2861134Z Failures
2019-11-15T23:11:45.2868479Z  - msys2 (exited 1) - msys2 not installed. An error occurred during installation:
2019-11-15T23:11:45.7454841Z 
2019-11-15T23:11:45.7454841Z 
2019-11-15T23:11:45.7553379Z ##[error]Bash exited with code '1'.
2019-11-15T23:11:45.7740963Z ##[section]Starting: Checkout
2019-11-15T23:11:45.7867422Z ==============================================================================
2019-11-15T23:11:45.7867546Z Task         : Get sources
2019-11-15T23:11:45.7867643Z Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[bors]

💔 Test failed - checks-azure

[ehuss]

@bors retry
timeout installing msys2

[bors]

⌛ Testing commit a902383 with merge 9b0214d...

[bors]

☀️ Test successful - checks-azure
Approved by: alexcrichton
Pushing 9b0214d to master...