TypeError: Cannot read property 'map' of undefined

[Turbo87]

TypeError: Cannot read property 'map' of undefined
    at _loop_1 (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:271:51)
    at Changelog.fillInCategories (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:279:13)
    at Changelog.<anonymous> (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:76:30)
    at step (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:32:23)
    at Object.next (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:13:53)
    at fulfilled (/Users/tbieniek/Code/glimmer.js/node_modules/lerna-changelog/lib/changelog.js:4:58)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:169:7)

after running yarn changelog --tag-from v0.4.0 in https://github.com/glimmerjs/glimmer.js

[evocateur]

Glimmer doesn't have a lerna.json or changelog field in package.json, how is lerna-changelog supposed to work there?

[Turbo87]

Sorry, forgot to mention glimmerjs/glimmer.js#27