Rustig dependency fails to build on stable

[MichaelMauderer]

One of the dependencies fails to build with the following error:

 Compiling cpp_demangle v0.2.9
error[E0034]: multiple applicable items in scope
    --> C:\Users\mail\.cargo\registry\src\github.com-1ecc6299db9ec823\petgraph-0.4.12\src\graph_impl\stable_graph\mod.rs:1171:19
     |
1171 |         self.iter.find_map(|(i, node)| {
     |                   ^^^^^^^^ multiple `find_map` found
     |
note: candidate #1 is defined in an impl of the trait `iter_utils::IterUtilsExt` for the type `_`

It seems this is fixed in a newer minor point release of the dependency (i.e., cpp_demangle version 0.2.12).

It might be good to allow automatic upgrades of the rustig dependencies to newer minor point releases.

[ckaran]

This seems to still be here, and may have grown a bit. rustc --version yields rustc 1.31.1 (b6c32da9b 2018-12-18). The output from cargo install --git https://github.com/Technolution/rustig rustig -vvv ends with the following (I'm cutting off the successful parts of the compile)

     Running `rustc --crate-name syn /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/syn-0.11.11/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="quote"' --cfg 'feature="synom"' --cfg 'feature="unicode-xid"' -C metadata=60e8baaae9b77804 -C extra-filename=-60e8baaae9b77804 --out-dir /tmp/cargo-installYBfg34/release/deps -L dependency=/tmp/cargo-installYBfg34/release/deps --extern quote=/tmp/cargo-installYBfg34/release/deps/libquote-ee82c96dc9689f06.rlib --extern synom=/tmp/cargo-installYBfg34/release/deps/libsynom-300bc64acc31568d.rlib --extern unicode_xid=/tmp/cargo-installYBfg34/release/deps/libunicode_xid-ea2dbfdbee9e4824.rlib --cap-lints warn`
error[E0034]: multiple applicable items in scope                                                                                                                             
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/graph_impl/stable_graph/mod.rs:1171:19                                            
     |                                                                                                                                                                       
1171 |         self.iter.find_map(|(i, node)| {                                                                                                                              
     |                   ^^^^^^^^ multiple `find_map` found                                                                                                                  
     |                                                                                                                                                                       
note: candidate #1 is defined in an impl of the trait `iter_utils::IterUtilsExt` for the type `_`                                                                            
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/iter_utils.rs:5:5                                                                 
     |                                                                                                                                                                       
5    | /     fn find_map<F, R>(&mut self, mut f: F) -> Option<R>                                                                                                             
6    | |         where F: FnMut(Self::Item) -> Option<R>                                                                                                                     
7    | |     {                                                                                                                                                               
8    | |         while let Some(elt) = self.next() {                                                                                                                         
...    |                                                                                                                                                                     
13   | |         None                                                                                                                                                        
14   | |     }                                                                                                                                                               
     | |_____^                                                                                                                                                               
     = note: candidate #2 is defined in an impl of the trait `std::iter::Iterator` for the type `std::iter::Enumerate<_>`                                                    
                                                                                                                                                                             
error[E0034]: multiple applicable items in scope                                                                                                                             
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/graph_impl/stable_graph/mod.rs:1363:19                                            
     |                                                                                                                                                                       
1363 |         self.iter.find_map(|(i, edge)|                                                                                                                                
     |                   ^^^^^^^^ multiple `find_map` found                                                                                                                  
     |                                                                                                                                                                       
note: candidate #1 is defined in an impl of the trait `iter_utils::IterUtilsExt` for the type `_`                                                                            
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/iter_utils.rs:5:5                                                                 
     |                                                                                                                                                                       
5    | /     fn find_map<F, R>(&mut self, mut f: F) -> Option<R>                                                                                                             
6    | |         where F: FnMut(Self::Item) -> Option<R>                                                                                                                     
7    | |     {                                                                                                                                                               
8    | |         while let Some(elt) = self.next() {                                                                                                                         
...    |                                                                                                                                                                     
13   | |         None                                                                                                                                                        
14   | |     }                                                                                                                                                               
     | |_____^                                                                                                                                                               
     = note: candidate #2 is defined in an impl of the trait `std::iter::Iterator` for the type `std::iter::Enumerate<_>`                                                    
                                                                                                                                                                             
error[E0034]: multiple applicable items in scope                                                                                                                             
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/graph_impl/stable_graph/mod.rs:1527:19                                            
     |                                                                                                                                                                       
1527 |         self.iter.find_map(|(i, node)| {                                                                                                                              
     |                   ^^^^^^^^ multiple `find_map` found                                                                                                                  
     |                                                                                                                                                                       
note: candidate #1 is defined in an impl of the trait `iter_utils::IterUtilsExt` for the type `_`                                                                            
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/iter_utils.rs:5:5                                                                 
     |                                                                                                                                                                       
5    | /     fn find_map<F, R>(&mut self, mut f: F) -> Option<R>                                                                                                             
6    | |         where F: FnMut(Self::Item) -> Option<R>                                                                                                                     
7    | |     {                                                                                                                                                               
8    | |         while let Some(elt) = self.next() {                                                                                                                         
...    |                                                                                                                                                                     
13   | |         None                                                                                                                                                        
14   | |     }                                                                                                                                                               
     | |_____^                                                                                                                                                               
     = note: candidate #2 is defined in an impl of the trait `std::iter::Iterator` for the type `std::iter::Enumerate<_>`                                                    
                                                                                                                                                                             
error[E0034]: multiple applicable items in scope                                                                                                                             
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/graph_impl/stable_graph/mod.rs:1573:19                                            
     |                                                                                                                                                                       
1573 |         self.iter.find_map(|(i, node)| {                                                                                                                              
     |                   ^^^^^^^^ multiple `find_map` found                                                                                                                  
     |                                                                                                                                                                       
note: candidate #1 is defined in an impl of the trait `iter_utils::IterUtilsExt` for the type `_`                                                                            
    --> /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/iter_utils.rs:5:5                                                                 
     |                                                                                                                                                                       
5    | /     fn find_map<F, R>(&mut self, mut f: F) -> Option<R>                                                                                                             
6    | |         where F: FnMut(Self::Item) -> Option<R>                                                                                                                     
7    | |     {                                                                                                                                                               
8    | |         while let Some(elt) = self.next() {                                                                                                                         
...    |                                                                                                                                                                     
13   | |         None                                                                                                                                                        
14   | |     }                                                                                                                                                               
     | |_____^                                                                                                                                                               
     = note: candidate #2 is defined in an impl of the trait `std::iter::Iterator` for the type `std::iter::Enumerate<_>`                                                    
                                                                                                                                                                             
error: aborting due to 4 previous errors                                                                                                                                     
                                                                                                                                                                             
For more information about this error, try `rustc --explain E0034`.                                                                                                          
error: Could not compile `petgraph`.                                                                                                                                         

Caused by:
  process didn't exit successfully: `rustc --crate-name petgraph /home/cfkaran2/.cargo/registry/src/github.com-1ecc6299db9ec823/petgraph-0.4.12/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="graphmap"' --cfg 'feature="ordermap"' --cfg 'feature="stable_graph"' -C metadata=79f065092ff5e915 -C extra-filename=-79f065092ff5e915 --out-dir /tmp/cargo-installYBfg34/release/deps -L dependency=/tmp/cargo-installYBfg34/release/deps --extern fixedbitset=/tmp/cargo-installYBfg34/release/deps/libfixedbitset-8be211e2e114f54f.rlib --extern ordermap=/tmp/cargo-installYBfg34/release/deps/libordermap-dde59567801968dd.rlib --cap-lints warn` (exit code: 1)
warning: build failed, waiting for other jobs to finish...
error: failed to compile `rustig v0.2.0 (https://github.com/Technolution/rustig#38518668)`, intermediate artifacts can be found at `/tmp/cargo-installYBfg34`                

Caused by:
  build failed