ExoPlayer migration script does not work with variable and shows malformed message

Media3 Version

ExoPlayer 2.18.7

Devices that reproduce the issue

PC, Windows v11, Windows Linux Subsystem v2 running Ubuntu 20.04.4 LTS

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

1. Create an Android library. In its module-level build.gradle define a variable def exoPlayerVersion = "2.18.7" and add dependency from ExoPlayer:

   def exoPlayerVersion = "2.18.7"
   
   dependencies {
       api "com.google.android.exoplayer:exoplayer-core:${exoPlayerVersion}"
       api "com.google.android.exoplayer:exoplayer-ui:${exoPlayerVersion}"
   }
   

2. Download migration script for v2.18.7 and follow instructions in Migration Guide
3. As guide instructs, run the script with -l option:

   ./media3-migration.sh -l .   # script is run from library module folder
   

Expected result

The outcome of -l command: the set of files that are selected for migration.

Actual result

[...omitted...]$ ./media3-migration.sh -l .
=============================================
Validation errors (use -f to force execution)
---------------------------------------------
' found in version does not match '2.18.7'. Update to '2.18.7' or use the migration script matching your current version. Current version '${exoPlayerVersion}
    ./my-module-name/build.gradle

What we can see here is that:

1. use of variable in dependency does not seem to be supported. If that's the case, can we file a PR to documentation mentioning that?

2. the error message seems malformed. It starts with a single quote, probably there is some part before missing. Also the ending seems corrupted (Current version '${exoPlayerVersion}). But a quick check on current script did not help to understand what's going on.

Media

No media needed

Bug Report

• You will email the zip file produced by adb bugreport to dev.exoplayer@gmail.com after filing this issue.