Cannot get output from exec.exec or exec.getExecOutput

Describe the bug
When executing a command using exec.exec or exec.getExecOutput, I cannot get the output of the command. I can see the command output in live web console, but when printing the output (constructed through listeners.stdout), it's empty. Similarly, the getExecOutput helper function also returns empty output.

async function configure () {
  // Get configurations
  const config = await getConfig()

  const keyFile = 'private.key'
  await fs.promises.writeFile(keyFile, config.gitUserSigningKey)
  const { stdout } = await exec.getExecOutput('gpg', ['--import', keyFile])

  // stdout is empty!
}

async function configure () {
  // Get configurations
  const config = await getConfig()

  let cmdOutput = ''
  const options = {
    listeners: {
      stdout: (data) => { cmdOutput += data.toString() }
    }
  }
 
  const keyFile = 'private.key'
  await fs.promises.writeFile(keyFile, config.gitUserSigningKey)
  await exec.exec('gpg', ['--import', keyFile], options)

  // stdout is empty!
}

Start by reproducing the issue through exec.exec and exec.getExecOutput with the gpg command shown, comparing the live console output with listeners.stdout and the returned stdout. Trace how command output is captured and returned; done means both APIs expose the command's stdout consistently.