Compilation errors in Debian 9

Ran $ cargo build and rustc (ver 1.24.1) output the following:

   Compiling loop-rs v0.4.0 (file:///home/um-li/Downloads/Loop)
error: non-reference pattern used to match a reference (see issue #42640)
  --> src/main.rs:99:20
   |
99 |             if let Some(string) = &opt.until_contains {
   |                    ^^^^^^^^^^^^ help: consider using a reference: `&Some(string)`

error: non-reference pattern used to match a reference (see issue #42640)
   --> src/main.rs:106:20
    |
106 |             if let Some(regex) = &opt.until_match {
    |                    ^^^^^^^^^^^ help: consider using a reference: `&Some(regex)`

error: non-reference pattern used to match a reference (see issue #42640)
   --> src/main.rs:114:16
    |
114 |         if let Some(error_code) = &opt.until_error {
    |                ^^^^^^^^^^^^^^^^ help: consider using a reference: `&Some(error_code)`

error: non-reference pattern used to match a reference (see issue #42640)
   --> src/main.rs:116:17
    |
116 |                 ErrorCode::Any => if !result.exit_status.success() {
    |                 ^^^^^^^^^^^^^^ help: consider using a reference: `&ErrorCode::Any`

error: non-reference pattern used to match a reference (see issue #42640)
   --> src/main.rs:119:17
    |
119 |                 ErrorCode::Code(code) =>  {
    |                 ^^^^^^^^^^^^^^^^^^^^^ help: consider using a reference: `&ErrorCode::Code(code)`

error: aborting due to 5 previous errors

error: Could not compile `loop-rs`.

Start by running cargo build with rustc 1.24.1 and inspect the reported locations in src/main.rs: lines 99, 106, and 114-119. Verify the compatibility issue is addressed at those matches, then rerun the build on Debian 9; done means compilation succeeds without these errors.