mbenfield@mbenfield:~/Code$ git clone https://github.com/steveklabnik/semver-parser
<...snip...>
mbenfield@mbenfield:~/Code$ cd semver-parser/
mbenfield@mbenfield:~/Code/semver-parser$ git checkout 4ad3c7b10496d0007af2f327cb50a9897b5b969f
<...snip...>
mbenfield@mbenfield:~/Code/semver-parser$ rustup default 1.52.1
<...snip...>
mbenfield@mbenfield:~/Code/semver-parser$ cargo build
    Updating crates.io index
   Compiling ucd-trie v0.1.3
   Compiling pest v2.1.3
   Compiling semver-parser v0.10.1 (/usr/local/google/home/mbenfield/Code/semver-parser)
error: custom inner attributes are unstable
 --> src/generated.rs:4:4
  |
4 | #![rustfmt::skip]
  |    ^^^^^^^^^^^^^
  |
  = note: `#[deny(soft_unstable)]` on by default
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
  = note: for more information, see issue #64266 <https://github.com/rust-lang/rust/issues/64266>

error: aborting due to previous error

error: could not compile `semver-parser`

To learn more, run the command again with --verbose.
mbenfield@mbenfield:~/Code/semver-parser$ rustup default 1.51.0
<...snip...>
mbenfield@mbenfield:~/Code/semver-parser$ cargo build
   Compiling ucd-trie v0.1.3
   Compiling pest v2.1.3
   Compiling semver-parser v0.10.1 (/usr/local/google/home/mbenfield/Code/semver-parser)
    Finished dev [unoptimized   debuginfo] target(s) in 3.56s