use of `unwrap_or_else` to construct default value

use of `unwrap_or_else` to construct default value

could not compile `emulsion` (bin "emulsion") due to 2 previous errors

The process '/home/runner/.cargo/bin/cargo' failed with exit code 101

Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions-rs/toolchain@v1, actions/checkout@v2, actions-rs/cargo@v1. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.

The following actions uses node12 which is deprecated and will be forced to run on node16: actions-rs/toolchain@v1, actions/checkout@v2, actions-rs/cargo@v1. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/