Caused by:

  process didn't exit successfully:
  `/WRKOBJDIR/lang/rust/work/rust-1.19.0-x86_64-unknown-netbsd/rustc/bin/rustc
  - --crate-name ___ --print=file-names --crate-type bin --crate-type
  rlib --target x86_64-unknown-netbsd` (exit code: 101)
--- stderr
error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report:
https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

thread 'rustc' panicked at 'failed to get current_exe: No such file or
directory (os error 2)',
/checkout/src/librustc/session/filesearch.rs:169

note: Run with `RUST_BACKTRACE=1` for a backtrace.


Traceback (most recent call last):
  File "./x.py", line 20, in <module>
    bootstrap.main()
  File "/WRKOBJDIR/lang/rust/work/rustc-1.20.0-src/src/bootstrap/bootstrap.py", line 694, in main
    bootstrap()
  File "/WRKOBJDIR/lang/rust/work/rustc-1.20.0-src/src/bootstrap/bootstrap.py", line 675, in bootstrap
    rb.build_bootstrap()
  File
  "/WRKOBJDIR/lang/rust/work/rustc-1.20.0-src/src/bootstrap/bootstrap.py",
  line 423, in build_bootstrap

    run(args, env=env, verbose=self.verbose)
  File "/WRKOBJDIR/lang/rust/work/rustc-1.20.0-src/src/bootstrap/bootstrap.py", line 147, in run
    raise RuntimeError(err)

RuntimeError: failed to run:
  /WRKOBJDIR/lang/rust/work/rust-1.19.0-x86_64-unknown-netbsd/cargo/bin/cargo
  build --manifest-path
  /WRKOBJDIR/lang/rust/work/rustc-1.20.0-src/src/bootstrap/Cargo.toml
  --verbose --verbose --frozen

*** Error code 1

Stop.
make[1]: stopped in /usr/pkgsrc/lang/rust
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/rust

＠ after /procfs mounted:

CF-SX2# cat /etc/fstab 
procfs          /proc   procfs  rw
kernfs          /kern   kernfs  rw
ptyfs           /dev/pts        ptyfs   rw