[BUG] Postinstall does not output anything from script (even with loglevel=silly) #3347

$ npm i --loglevel silly
npm verb cli [
npm verb cli   '/usr/bin/node',
npm verb cli   '/home/hasezoey/.npm-packages/bin/npm',
npm verb cli   'i',
npm verb cli   '--loglevel',
npm verb cli   'silly'
npm verb cli ]
npm info using [email protected]
npm info using [email protected]
npm timing npm:load:whichnode Completed in 1ms
npm timing config:load:defaults Completed in 1ms
npm timing config:load:file:/home/hasezoey/.npm-packages/lib/node_modules/npm/npmrc Completed in 1ms
npm timing config:load:builtin Completed in 1ms
npm timing config:load:cli Completed in 2ms
npm timing config:load:env Completed in 0ms
npm timing config:load:file:/home/hasezoey/Downloads/npm-postinstall/root-package/.npmrc Completed in 1ms
npm timing config:load:project Completed in 1ms
npm timing config:load:file:/home/hasezoey/.npmrc Completed in 0ms
npm timing config:load:user Completed in 0ms
npm timing config:load:file:/home/hasezoey/.npm-packages/etc/npmrc Completed in 0ms
npm timing config:load:global Completed in 0ms
npm timing config:load:validate Completed in 1ms
npm timing config:load:credentials Completed in 0ms
npm timing config:load:setEnvs Completed in 1ms
npm timing config:load Completed in 7ms
npm timing npm:load:configload Completed in 7ms
npm timing npm:load:setTitle Completed in 0ms
npm timing npm:load:setupLog Completed in 1ms
npm timing npm:load:cleanupLog Completed in 1ms
npm timing npm:load:configScope Completed in 0ms
npm timing npm:load:projectScope Completed in 0ms
npm timing npm:load Completed in 12ms
npm timing config:load:flatten Completed in 1ms
npm timing arborist:ctor Completed in 1ms
npm timing idealTree:init Completed in 7ms
npm timing idealTree:userRequests Completed in 0ms
npm sill idealTree buildDeps
npm timing idealTree:#root Completed in 1ms
npm timing idealTree:buildDeps Completed in 1ms
npm timing idealTree:fixDepFlags Completed in 0ms
npm timing idealTree Completed in 8ms
npm timing reify:loadTrees Completed in 8ms
npm timing reify:diffTrees Completed in 0ms
npm sill reify moves {}
npm timing reify:retireShallow Completed in 1ms
npm timing reify:createSparse Completed in 0ms
npm timing reify:loadBundles Completed in 0ms
npm sill audit bulk request { postinstall_package: [ '1.0.0' ] }
npm timing reifyNode:node_modules/postinstall-package Completed in 18ms
npm timing reify:unpack Completed in 18ms
npm timing reify:unretire Completed in 0ms
npm timing build:queue Completed in 0ms
npm timing build:deps Completed in 1ms
npm timing build:queue Completed in 0ms
npm info run [email protected] postinstall ../postinstall-package node ./postinstall.js
npm info run [email protected] postinstall { code: 0, signal: null }
npm timing build:run:postinstall:../postinstall-package Completed in 25ms
npm timing build:run:postinstall Completed in 26ms
npm timing build:links Completed in 26ms
npm timing build Completed in 27ms
npm timing reify:build Completed in 27ms
npm timing reify:trash Completed in 0ms
npm timing reify:save Completed in 2ms
npm http fetch POST 200 https://registry.npmjs.org/-/npm/v1/security/advisories/bulk 490ms
npm timing auditReport:getReport Completed in 492ms
npm sill audit report {}
npm timing auditReport:init Completed in 0ms
npm timing reify:audit Completed in 494ms
npm timing reify Completed in 510ms
npm sill ADD node_modules/postinstall-package

added 1 package, and audited 3 packages in 656ms

found 0 vulnerabilities
npm timing command:install Completed in 521ms
npm verb exit 0
npm timing npm Completed in 660ms
npm info ok

prefix=/home/hasezoey/.npm-packages
sign-git-tag=true