clipboard-win's license (which is BSL) seems not compatible MIT license

[TheWaWaR]

The error log when use cargo deny to check the license:

cargo deny check --hide-inclusion-graph --show-stats licenses                                                                                                                                                                                                                     
error[L001]: failed to satisfy license requirements                                                                                                                                                                                                                               
  ┌─ error-code 2.3.1 (registry+https://github.com/rust-lang/crates.io-index):4:12                                                                                                                                                                                                
  │                                                                                                                                                                                                                                                                               
4 │ license = "BSL-1.0"                                                                                                                                                                                                                                                           
  │            ^^^^^^^                                                                                                                                                                                                                                                            
  │            │                                                                                                                                                                                                                                                                  
  │            license expression retrieved via Cargo.toml `license`                                                                                                                                                                                                              
  │            rejected: not explicitly allowed                                                                                                                                                                                                                                   

error[L001]: failed to satisfy license requirements                                                                                                                                                                                                                               
  ┌─ str-buf 1.0.6 (registry+https://github.com/rust-lang/crates.io-index):4:12                                                                                                                                                                                                   
  │                                                                                                                                                                                                                                                                               
4 │ license = "BSL-1.0"                                                                                                                                                                                                                                                           
  │            ^^^^^^^                                                                                                                                                                                                                                                            
  │            │                                                                                                                                                                                                                                                                  
  │            license expression retrieved via Cargo.toml `license`                                                                                                                                                                                                              
  │            rejected: not explicitly allowed                                                                                                                                                                                                                                   

error[L001]: failed to satisfy license requirements                                                                                                                                                                                                                               
  ┌─ clipboard-win 4.4.1 (registry+https://github.com/rust-lang/crates.io-index):4:12                                                                                                                                                                                             
  │                                                                                                                                                                                                                                                                               
4 │ license = "BSL-1.0"                                                                                                                                                                                                                                                           
  │            ^^^^^^^                                                                                                                                                                                                                                                            
  │            │                                                                                                                                                                                                                                                                  
  │            license expression retrieved via Cargo.toml `license`                                                                                                                                                                                                              
  │            rejected: not explicitly allowed                                                                                                                                                                                                                                   

 licenses FAILED: 3 errors, 0 warnings

[gwenn]

Should we make this dependency optional ? Or find an alternative ?

[TheWaWaR]

Find an alternative is good. Make this dependency optional is ok, since some unimportant features not supported is acceptable.

[DoumanAsh]

JFYI the difference between BSL and MIT is that BSL explicitly states allowed things while MIT is vague license (effectively making it iffy for use in commercial organizations) BSL allows safe commercial use and distribution without limitations hence cargo deny is stupid The only real 'limitation' is that you MUST distribute copy of license if you distribute modified source code (not in compiled form)