Maybe "block" here?

[bestgopher]

GoProgrammingFromBeginnerToMaster/chapter8/sources/pprof_standalone1.go

Line 69 in d3e5793

if mp := pprof.Lookup("mutex"); mp != nil {

[bigwhite]

Could you give us more detail about why this line maybe block?

[bestgopher]

@bigwhite

[bigwhite]

Got it! I have fixed it in source code and add an entry to the errata.md.