gitgraph / init pattern for non-default mainbranch name fails..

[byronfa]

I was trying to use this example from mermaid documentation, and it appears non-functional in the plugin.. 'am I missing something? Seems to generally understand that there's a new branch, but merging from it later doesn't work.

%%{init: { 'logLevel': 'debug', 'theme': 'base', 'gitGraph': {'showBranches': true, 'showCommitLabel':true,'mainBranchName': 'MetroLine1'}} }%%
      gitGraph
        commit id:"NewYork"
        commit id:"Dallas"
        branch MetroLine2
        commit id:"LosAngeles"
        commit id:"Chicago"
        commit id:"Houston"
        branch MetroLine3
        commit id:"Phoenix"
        commit type: HIGHLIGHT id:"Denver"
        commit id:"Boston"
        checkout MetroLine1
        commit id:"Atlanta"
        merge MetroLine3
        commit id:"Miami"
        commit id:"Washington"
        merge MetroLine2 tag:"MY JUNCTION"
        commit id:"Boston"
        commit id:"Detroit"
        commit type:REVERSE id:"SanFrancisco"

[axlee39]

This is the error message the preview gives:

Trying to checkout branch which is not yet created. (Help try using "branch MetroLine1")

[mjbvz]

Seems to be fixed in v1.21.0 of this extension which includes mermaid 10.6.1