Fails to build when patching from git

[dangeross]

I'm having trouble building from a patch when the source is git. The patching works fine when the patch is defined as a path. I first thought it was my forked repo that was causing the error, but even patching from this repo causes the same error.

[dependencies]
openssl = { version = "0.10.62", features = ["vendored"] }

[patch.crates-io]
openssl-src = { git = "https://github.com/alexcrichton/openssl-src-rs.git", tag = "300.2.1+3.2.0" }

error: failed to run custom build command for `openssl-sys v0.9.98`

Caused by:
  process didn't exit successfully: `/Users/dangross/Source/Projects/breez-sdk/libs/sdk-wasm/target/release/build/openssl-sys-9b34fa47009423a2/build-script-main` (exit status: 101)
  --- stdout
  cargo:rerun-if-env-changed=WASM32_WASMER_WASI_OPENSSL_NO_VENDOR
  WASM32_WASMER_WASI_OPENSSL_NO_VENDOR unset
  cargo:rerun-if-env-changed=OPENSSL_NO_VENDOR
  OPENSSL_NO_VENDOR unset

  --- stderr
  thread 'main' panicked at /Users/dangross/.cargo/git/checkouts/openssl-src-rs-2e32af6c1ebd97b1/47d047a/src/lib.rs:644:35:
  called `Result::unwrap()` on an `Err` value: Error { kind: InvalidInput, message: "the source path is neither a regular file nor a symlink to a regular file" }
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...

It is failing on this line:

openssl-src-rs/src/lib.rs

Line 644 in 47d047a

fs::copy(&path, &dst).unwrap();

Error { kind: InvalidInput, message: "the source path is neither a regular file nor a symlink to a regular file" }

when copying openssl/cloudflare-quiche/fuzz/mayhem/qpack_decode/corpus which is a symlink to the openssl/cloudflare-quiche/fuzz/corpus/qpack_decode directory.