The project doesn't build

[mik01aj]

Doing cargo build on current master fails with:

   Compiling clipboard v0.5.0                                                                                                                         
error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)                                
  --> /usr/local/google/home/mikoda/.cargo/git/checkouts/cursive-2b944efb52182bd6/b722f8a/src/backend/puppet/mod.rs:75:17                             
   |                                                                                                                                                  
12 | use crate::backend;                                                                                                                              
   |     -------------- not an extern crate passed with `--extern`                                                                                    
...                                                                                                                                                   
75 |             use backend::Backend;                                                                                                                
   |                 ^^^^^^^                                                                                                                          
   |                                                                                                                                                  
note: this import refers to the module imported here                                                                                                  
  --> /usr/local/google/home/mikoda/.cargo/git/checkouts/cursive-2b944efb52182bd6/b722f8a/src/backend/puppet/mod.rs:12:5                              
   |                                                                                                                                                  
12 | use crate::backend;                                                                                                                              
   |     ^^^^^^^^^^^^^^                                                                                                                               
                                                                                                                                                      
error: aborting due to previous error                                                                                                                 
                                                                                                                                                      
For more information about this error, try `rustc --explain E0658`.                                                                                   
error: Could not compile `cursive`.                                                                                                                   
warning: build failed, waiting for other jobs to finish...
error: build failed                  

I also tried to look for older working commits on https://travis-ci.org/njskalski/sly-editor, but it says: "You don't have sufficient rights to enable this repo on Travis. Please contact the admin to enable it or to receive admin rights yourself."