Web flamegraph sometimes crashes with "startsWith of undefined" (rack-mini-profiler)

[danny-pflughoeft]

When used to view traces recorded by rack-mini-profiler, the web-based flamegraph sometimes crashes with the following error

speedscope.44364064.js:174 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'startsWith')

The minified code is

for(let t of this.frames)t.name.startsWith("__Z")&& ...

which appears to be the call on this line

[danny-pflughoeft]

I've confirmed this is an issue with all stackprof-generated flamegraphs, not just ones from rack-mini-profiler

[jez]

I've opened a PR which should fix this: #419