Unable to build project with Node >15

[Simon Egersand]

Using Node 15.4.0 I'm unable to run gitbook build.

$ gitbook build
Installing GitBook 3.2.3
  SOLINK_MODULE(target) Release/.node
  CXX(target) Release/obj.target/fse/fsevents.o
  SOLINK_MODULE(target) Release/fse.node
  SOLINK_MODULE(target) Release/.node
  CXX(target) Release/obj.target/fse/fsevents.o
  SOLINK_MODULE(target) Release/fse.node
/usr/local/lib/node_modules/gitbook-cli/node_modules/npm/node_modules/graceful-fs/polyfills.js:287
      if (cb) cb.apply(this, arguments)
                 ^

TypeError: cb.apply is not a function
    at /usr/local/lib/node_modules/gitbook-cli/node_modules/npm/node_modules/graceful-fs/polyfills.js:287:18
    at FSReqCallback.oncomplete (node:fs:200:5)

I've tried the usual tricks found by Googling to no avail.