Probabilistic compile failure on Windows Server 2016 for target i686-pc-windows-msvc

**# version:**
openssl-src-111.15.0+1.1.1k

**run:**
cargo build --release --target i686-pc-windows-msvc

may fail **report:**
{ code: 32, kind: Other, message: "The process cannot access the file because it is being used by another process." }
at
openssl-src-111.15.0+1.1.1k\src\lib.rs:456:40, which is:
fs::remove_dir_all(&inner_dir).unwrap();

**detail:**
` created directory `C:/pipeline-255714-1/target/i686-pc-windows-msvc/release/build/openssl-sys-07fd305febe929f0/out/openssl-build/install/lib'
Copying: libcrypto.lib to C:/pipeline-255714-1/target/i686-pc-windows-msvc/release/build/openssl-sys-07fd305febe929f0/out/openssl-build/install/lib/libcrypto.lib
Copying: libssl.lib to C:/pipeline-255714-1/target/i686-pc-windows-msvc/release/build/openssl-sys-07fd305febe929f0/out/openssl-build/install/lib/libssl.lib
Copying: ossl_static.pdb to C:/pipeline-255714-1/target/i686-pc-windows-msvc/release/build/openssl-sys-07fd305febe929f0/out/openssl-build/install/lib/ossl_static.pdb

--- stderr

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

Microsoft (R) Program Maintenance Utility Version 14.29.30133.0
Copyright (C) Microsoft Corporation. All rights reserved.

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 32, kind: Other, message: "The process cannot access the file because it is being used by another process." }', C:\Windows\system32\config\systemprofile\.cargo\registry\src\github.com-1ecc6299db9ec823\openssl-src-111.15.0+1.1.1k\src\lib.rs:456:40
[2021-09-02 19:22:06] note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[2021-09-02 19:22:06]The command "cargo build --release --target i686-pc-windows-msvc" exited with 101. `

**Then** I add a line before it to print var inner_dir :
panic!("inner_dir {:?}", inner_dir);
` thread 'main' panicked at 'inner_dir "C:\\-pipeline-255714-1\\target\\i686-pc-windows-msvc\\release\\build\\openssl-sys-07fd305febe929f0\\out\\openssl-build\\build\\src"', C:\Users\Administrator\.cargo\registry\src\github.com-1ecc6299db9ec823\openssl-src-111.15.0+1.1.1k\src\lib.rs:456:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace`

That means program failed during **removing** build\src dir.

Then I add a line to **sleep** 1s before rm dir, it seems resolved. # #
std:: thread ::sleep(std::time::Duration::from_millis(1000));