CLI command `extract --overwrite` deletes msgstr values in source locale po file

Describe the bug

The first time lingui extract --overwrite is run then it generates po file entries for the source locale with identical msgid and msgstr values, e.g.

#: src/file.ts:105
msgid "Hello world"
msgstr "Hello world"

But then future runs of lingui extract --overwrite will remove the msgstr values in existing unedited entries, and changes the above to,

#: src/file.ts:105
msgid "Hello world"

This renders the source locale po file seemingly invalid, and breaks integrations with some cloud translation services like CrowdIn with errors like The imported messages.po localization file is invalid. GetText PO validation module said: line ###: missing msgstr section.

To Reproduce

Config looks like

module.exports = {
  sourceLocale: 'en',
  srcPathDirs: ['<rootDir>/src'],
  format: 'po',
  sorting: 'origin',
  localeDir: '<rootDir>/src/locale',
}

And we’re just using the plain JS approach (not React), e.g.

import { t } from '@lingui/macro'
i18n._(t`Hello world`)

Expected behavior

Repeated runs of lingui extract --overwrite do not remove msgstr entries for existing translations in the source locale po file. Although this is an assumption, and my understanding of the process may be faulty.

Additional context

Add any other context about the problem here.

• jsLingui version 2.9.1
• Babel version babel-core@7.0.0-bridge.0
• Your Babel config

module.exports = {
  presets: [
    [
      '@babel/preset-env',
      {
        targets: {
          node: '10',
        },
        modules: 'cjs',
      },
    ],
    '@babel/typescript',
  ],
  plugins: [
    '@babel/proposal-class-properties',
    '@babel/proposal-object-rest-spread',
    'macros',
  ],
}

[ThiefMaster]

any update on this? I don’t think it should be [wontfix]…

[stale[bot]]

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