react-native-git-upgrade breaks over yarn.lock?

[braco]

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Description

react-native-git-upgrade seems to fail with "error: yarn.lock: does not exist in index"

$ react-native-git-upgrade --version
0.2.7

$ react-native-git-upgrade

...
HEAD is now at 6f89aa9 Project snapshot
git-upgrade info Apply the patch
error: patch failed: .flowconfig:28
Falling back to three-way merge...
Applied patch to '.flowconfig' with conflicts.
error: patch failed: .gitignore:34
Falling back to three-way merge...
Applied patch to '.gitignore' with conflicts.
error: patch failed: android/app/src/main/java/com/ditto/MainApplication.java:17
Falling back to three-way merge...
Applied patch to 'android/app/src/main/java/com/ditto/MainApplication.java' cleanly.
error: patch failed: ios/ditto.xcodeproj/project.pbxproj:22
Falling back to three-way merge...
Applied patch to 'ios/ditto.xcodeproj/project.pbxproj' with conflicts.
error: patch failed: ios/ditto.xcodeproj/xcshareddata/xcschemes/ditto.xcscheme:3
Falling back to three-way merge...
Applied patch to 'ios/ditto.xcodeproj/xcshareddata/xcschemes/ditto.xcscheme' cleanly.
error: patch failed: ios/ditto/AppDelegate.m:9
Falling back to three-way merge...
Applied patch to 'ios/ditto/AppDelegate.m' with conflicts.
error: patch failed: ios/ditto/Info.plist:4
Falling back to three-way merge...
Applied patch to 'ios/ditto/Info.plist' with conflicts.
error: yarn.lock: does not exist in index
git-upgrade WARN The upgrade process succeeded but there might be conflicts to be resolved. See above for the list of files that have merge conflicts.

Despite success message, none of the files in my project are changed.

Reproduction

yarn add react-native@0.39.x

react-native-git-upgrade

Solution

Not sure about solution. Tried to override .gitignore and add yarn.lock to a commit, didn't work

Additional Information

• React Native version: 0.39.x
• Platform: n/a
• Operating System: MacOS

[dwilt]

@braco sounds like a duplicate of #12112