Tests failing

[wbt]

This appears to be the same as closed issue #72.

Running npm test includes the following output:

> sh truffle_test_runner.sh

events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: spawn testrpc ENOENT
    at exports._errnoException (util.js:1020:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32)
    at onErrorNT (internal/child_process.js:376:16)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
    at Module.runMain (module.js:613:11)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:160:9)
    at bootstrap_node.js:507:3
events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: spawn testrpc ENOENT
    at exports._errnoException (util.js:1020:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32)
    at onErrorNT (internal/child_process.js:376:16)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
    at Module.runMain (module.js:613:11)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:160:9)
    at bootstrap_node.js:507:3
events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: spawn testrpc ENOENT
    at exports._errnoException (util.js:1020:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32)
    at onErrorNT (internal/child_process.js:376:16)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
    at Module.runMain (module.js:613:11)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:160:9)
    at bootstrap_node.js:507:3
events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: spawn testrpc ENOENT
    at exports._errnoException (util.js:1020:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32)
    at onErrorNT (internal/child_process.js:376:16)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
    at Module.runMain (module.js:613:11)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:160:9)
    at bootstrap_node.js:507:3
events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: spawn testrpc ENOENT
    at exports._errnoException (util.js:1020:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:197:32)
    at onErrorNT (internal/child_process.js:376:16)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
    at Module.runMain (module.js:613:11)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:160:9)
    at bootstrap_node.js:507:3
npm ERR! Test failed.  See above for more details.
PS> npm --version
6.9.0
PS> node --version
v6.17.1

The node version is set to 6.17.1 because that is part of the official installation instructions, shown right above the "Test" header line.
According to this comment, that's the issue:

You need to use node 7 minimum

So it seems there is a simultaneous conflicting requirement for the node version to be both less than and greater than 7.

Trying to use node v7[.10.1] gave an issue at the "npm install node-gyp" and "npm install" steps, because npm does not support Node.js v7.10.1...Supported releases of Node.js are the latest release of 6, 8, 9, 10, 11, 12. Proceeding anyway yielded the same test failure. I also tried Node versions 9, 11, and 12 with similar results...it didn't seem to matter which version of node was in use.
I also tried with global truffle installation at version none, v5, and v4. That didn't seem to matter either.

I also tried npm install -g testrpc which reported a deprecation warning in favor of ganache-cli (that switch was a while ago!) but success in adding [email protected]. That didn't help. I tried npm install -g ganache-cli which installed (@6.9.1) and the tests kept failing.