process module not found

proc-macro2-1.0.43 git:(master) ✗ cargo b --release
Compiling proc-macro2 v1.0.43 (/root/sgx/exp/lib/proc-macro2-1.0.43)
error[E0432]: unresolved imports `std::process`, `std::process`
--> build.rs:59:10
|
59 | use std::process::{self, Command};
| ^^^^^^^ ^^^^ no `process` in the root
| |
| could not find `process` in `std`

when i want to move proc-macro2 to Rust SGX, and i find an error in build.rs

Start by reproducing `cargo b --release` in proc-macro2-1.0.43 and inspect `build.rs` at line 59, where `std::process::{self, Command}` is imported. Check how Rust SGX provides or restricts `std::process`, then determine whether the build completes successfully in the SGX environment; the issue does not specify a target fix or test.

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