Unable to install consumers: Unexpected strict mode reserved word in node_modules/ejs/postinstall.js

[cesine]

Steps to reproduce

https://travis-ci.org/github/caolan/nodeunit/jobs/710077156

$ npm install

ejs@2.7.4 postinstall /home/travis/build/caolan/nodeunit/node_modules/ejs
node ./postinstall.js
/home/travis/build/caolan/nodeunit/node_modules/ejs/postinstall.js:9
let envDisable = isTrue(process.env.DISABLE_OPENCOLLECTIVE) || isTrue(process.
^^^
SyntaxError: Unexpected strict mode reserved word
at exports.runInThisContext (vm.js:73:16)
at Module._compile (module.js:443:25)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Function.Module.runMain (module.js:501:10)
at startup (node.js:129:16)
at node.js:814:3

Root cause

let was introduced in a patch version v2.7.2...v2.7.3 (before the major version 3.x was cut which dropped support for older node versions)

Impact

Several projects are unable to build, including projects which directly or indirectly on the 194 projects which depend on nodeunit which is an older "stale" project that was widely used on these older versions of node.

https://www.npmjs.com/package/nodeunit

Solution

I can help make the patch to convert let to var, if you can make a branch on the upstream to represent the 2.x releases

(diff that would fix: cesine#1)