Crash on non-absolute path in Windows

[DutchGhost]

Problem

On windows, cargo crashes when "/" is used as a path for a dependency.

Backtrace

thread 'main' panicked at '`C:src\main.rs` is not absolute', src\tools\cargo\src/cargo\core\manifest.rs:286:9
stack backtrace:
   0:     0x7ff65be6e669 - git_odb_object_size
   1:     0x7ff65be9212b - git_odb_object_size
   2:     0x7ff65be65ac4 - git_odb_object_size
   3:     0x7ff65be72720 - git_odb_object_size
   4:     0x7ff65be7234a - git_odb_object_size
   5:     0x7ff65be72f78 - git_odb_object_size
   6:     0x7ff65be72ae4 - git_odb_object_size
   7:     0x7ff65be72a2f - git_odb_object_size
   8:     0x7ff65b989dfa - git_filter_source_repo
   9:     0x7ff65b98b474 - git_filter_source_repo
  10:     0x7ff65ba7a46e - git_index_checksum
  11:     0x7ff65b8f1c26 - git_filter_source_repo
  12:     0x7ff65b8e5be8 - git_filter_source_repo
  13:     0x7ff65b998808 - git_index_checksum
  14:     0x7ff65b952710 - git_filter_source_repo
  15:     0x7ff65b956c02 - git_filter_source_repo
  16:     0x7ff65b93031f - git_filter_source_repo
  17:     0x7ff65b9347df - git_filter_source_repo
  18:     0x7ff65ba58407 - git_index_checksum
  19:     0x7ff65bb05330 - git_index_checksum
  20:     0x7ff65bbde347 - git_filter_source_path
  21:     0x7ff65bb13884 - git_index_checksum
  22:     0x7ff65ba5ca2a - git_index_checksum
  23:     0x7ff65b8bd8bc - git_filter_source_repo
  24:     0x7ff65b8b573d - git_filter_source_repo
  25:     0x7ff65b8b2ac0 - git_filter_source_repo
  26:     0x7ff65b9a1511 - git_index_checksum
  27:     0x7ff65b99f74b - git_index_checksum
  28:     0x7ff65b99eca7 - git_index_checksum
  29:     0x7ff65b98eb92 - git_index_checksum
  30:     0x7ff65b98e640 - git_index_checksum
  31:     0x7ff65b73aafc - <unknown>
  32:     0x7ff65b74f82f - <unknown>
  33:     0x7ff65b798b57 - <unknown>
  34:     0x7ff65b784d66 - <unknown>
  35:     0x7ff65be72927 - git_odb_object_size
  36:     0x7ff65be80e62 - git_odb_object_size
  37:     0x7ff65be732b2 - git_odb_object_size
  38:     0x7ff65b79bcf7 - <unknown>
  39:     0x7ff65bfa94d4 - git_openssl_set_locking
  40:     0x7ffe00ff7974 - BaseThreadInitThunk
  41:     0x7ffe03c4a271 - RtlUserThreadStart

Steps

1. cargo new crash
2. cd crash
3. open Cargo.toml, and paste in x = {path = "/"} in the [dependencies] section
4. cargo build

Possible Solution(s)

On Windows, don't permit "/" as a path for a dependency?

Notes

Output of cargo version:
cargo 1.41.0-nightly (8280633 2019-11-11)
cargo 1.39.0 (1c6ec66 2019-09-30)

https://github.com/Evrey helped spark the idea of this bug

[retep998]

Technically / is a valid path on windows, it just doesn't mean what many people think it means.

[Thomasdezeeuw]

I've hit this as well, is the problem as simple as changing C:src\main.rs to C:\src\main.rs (a \ after C:)? If someone could point me to the related code I could give it a try.

[eminence]

Triage: As of rust 1.47, there is no crash. The error message you see now is the following:

error: failed to get `x` as a dependency of package `crash v0.1.0 (C:\Users\achin\tmp\27\crash)`

Caused by:
  failed to load source for dependency `x`

Caused by:
  Unable to update C:\

Caused by:
  failed to read `C:\Cargo.toml`

Caused by:
  The system cannot find the file specified. (os error 2)