Backtrace
```
14: tokio::runtime::handle::Handle::block_on
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.21/src/runtime/handle.rs:263
15: rustwide::cmd::Command::run_inner
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/cmd/mod.rs:426
16: rustwide::cmd::Command::run
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/cmd/mod.rs:292
17: rustwide::cmd::sandbox::SandboxImage::remote
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/cmd/sandbox.rs:33
18: rustwide::workspace::WorkspaceBuilder::init::{{closure}}
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/workspace.rs:152
19: std::panicking::try::do_call
at /home/joshua/.local/lib/rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libstd/panicking.rs:331
20: __rust_try
21: std::panicking::try
at /home/joshua/.local/lib/rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libstd/panicking.rs:274
22: std::panic::catch_unwind
at /home/joshua/.local/lib/rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libstd/panic.rs:394
23: rustwide::utils::file_lock
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/utils.rs:27
24: rustwide::workspace::WorkspaceBuilder::init
at /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/rustwide-0.7.1/src/workspace.rs:148
```
With a docker directory:
Without a docker directory: