Get stuck while running test after import hardhat-gas-reporter

Version Info:

• hardhat: 2.8.3
• hardhat-gas-reporter: 1.0.7
• OS：macOS Big Sur 11.6

Problem:
I get stuck when I run test after hardhat-gas-reporter was imported in hardhat.config.ts. The log of npm run test is listed below:

npm verb cli[⠂⠂⠂⠂⠂⸩ ⠧ : timing npm:load Completed in 27ms
npm verb cli   './.nvm/versions/node/v16.10.0/bin/node',
    npm verb cli   './.nvm/versions/node/v16.10.0/lib/node_modules/npm/bin/npm-cli.js',
        npm verb cli   'exec',
            npm verb cli   '--',
                npm verb cli   'hardhat',
                    npm verb cli   'test'
npm verb cli ]
npm info using npm @7.24.0
npm info using node @v16.10.0
npm timing npm: load:whichnode Completed in 1ms
npm timing config: load:defaults Completed in 1ms
npm timing config: load: file: /.nvm / versions / node / v16.10.0 / lib / node_modules / npm / npmrc Completed in 0ms
npm timing config: load:builtin Completed in 0ms
npm timing config: load:cli Completed in 2ms
npm timing config: load:env Completed in 0ms
npm timing config: load: file: [ProjectDir]/.npmrc Completed in 0ms
npm timing config: load:project Completed in 1ms
npm timing config: load: file: /.npmrc Completed in 0ms
npm timing config: load:user Completed in 0ms
npm timing config: load: file: /.nvm / versions / node / v16.10.0 / etc / npmrc Completed in 0ms
npm timing config: load: global Completed in 0ms
npm timing config: load:validate Completed in 1ms
npm timing config: load:credentials Completed in 1ms
npm timing config: load:setEnvs Completed in 0ms
npm timing config:load Completed in 6ms
npm timing npm: load:configload Completed in 6ms
npm timing npm: load:setTitle Completed in 15ms
npm timing npm: load:setupLog Completed in 0ms
npm timing config: load:flatten Completed in 3ms
npm timing npm: load:cleanupLog Completed in 1ms
npm timing npm: load:configScope Completed in 0ms
npm timing npm: load:projectScope Completed in 1ms
npm timing npm:load Completed in 31ms
Warning: loading secrets from tempalte file, might be invalid
⸨⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⸩ ⠧ : timing npm:load Completed in 27ms

Solution:
Try to modify the config of hardhat-gas-reporter with the following configuration:

gasReporter = {
    currency: 'USD',
    gasPrice: 21,
    enabled: (process.env.REPORT_GAS) ? true : false
}

Start in hardhat.config.ts and compare the hardhat-gas-reporter settings with the configuration shown in the issue. Run npm run test with the reporter imported, then verify that the command no longer gets stuck when REPORT_GAS is unset; the change is done when tests complete normally.