jhipster:upgrade never completes - jhipster

Question

UPDATE:
I performed my upgrade using the manual steps and it worked fine.
Afterwards, I noticed that version 4.3.0 has a new --verbose flag, so I ran it again with the --force flag. It still hangs with no error at yarn run webpack:build.
I then ran yarn webpack:build by itself. It looked like it completed everything, but did not return control to the console. I noticed a yellow message box in my taskbar notification area, that says 'JHipster' Notification Image. When I click on that notification, the job completes and control returns to the console. (I have noticed this notification looks different on Win10 and I don't think it requires a click to dismiss.)
This notification does not appear when running jhipster:upgrade, so I am guessing that is what is hanging up the process.
(original post)
I have generated a jhipster project (4.1.1) and have been working with it. I tried to run jhipster:upgrade to 4.2.0 but the process never completes. (I left it overnight.)
I set up and repeated this process on another computer, and it runs fine.
I have tried to identify why/where the process is hanging on my main computer but have been unsuccessful.
Anyone have some steps, tips to identify what is going wrong?
My environment:
Win7 Enterprise
java version "1.8.0_74"
git version 2.12.0.windows.1
node v6.10.2
yarn 0.21.3
Command output:
C:\applications\jhipster\formsLib>yo jhipster:upgrade
Welcome to the JHipster Upgrade Sub-Generator
This will upgrade your current application codebase to the latest JHipster version
Looking for latest generator-jhipster version...
New generator-jhipster version found: 4.2.0
Git repository detected
Updating generator-jhipster to 4.2.0 . This might take some time...
Several node processes kick off and run for a while, but then they go idle.
I have tried uninstalling and reinstalling node and yarn.
I enabled NODE_DEBUG=cluster,net,http,fs,tls,module,timers node and reran it. The last few lines before it stalls are:
NET 15272: _read
NET 15272: onread 21
NET 15272: got data
NET 15272: _read
NET 15272: onread 33
NET 15272: got data
NET 15272: _read
NET 15272: onread 73
NET 15272: got data
NET 15272: _read
process 15272 is node "C:\Users\mbaxley\AppData\Local\Yarn\config\global\node_modules\.bin\\..\yo\lib\cli.js" jhipster:upgrade
View Remaining Node Tasks
The only file updated during the process is the package.json file. Here is the diff of the modified file:
diff --git a/package.json b/package.json
index 7a2a6b8..eb7de34 100644
--- a/package.json
+++ b/package.json
## -16,11 +16,11 ##
"#angular/platform-browser-dynamic": "2.4.9",
"#angular/router": "3.4.9",
"#ng-bootstrap/ng-bootstrap": "1.0.0-alpha.21",
+ "angular2-cookie": "1.2.6",
"angular2-infinite-scroll": "0.3.4",
"bootstrap": "4.0.0-alpha.6",
- "font-awesome": "4.7.0",
- "angular2-cookie": "1.2.6",
"core-js": "2.4.1",
+ "font-awesome": "4.7.0",
"jquery": "3.1.1",
"ng-jhipster": "0.1.9",
"ng2-webstorage": "1.5.1",
## -47,7 +47,7 ##
"exports-loader": "0.6.4",
"extract-text-webpack-plugin": "2.1.0",
"file-loader": "0.10.1",
- "generator-jhipster": "4.1.1",
+ "generator-jhipster": "4.2.0",
"html-loader": "0.4.5",
"html-webpack-plugin": "2.28.0",
"image-webpack-loader": "3.2.0",
## -65,9 +65,12 ##
"lazypipe": "1.0.1",
"lodash": "4.17.4",
"map-stream": "0.0.6",
+ "node-sass": "4.5.0",
"phantomjs-prebuilt": "2.1.14",
+ "postcss-loader": "1.3.0",
"proxy-middleware": "0.15.0",
"run-sequence": "1.2.2",
+ "sass-loader": "5.0.1",
"sourcemap-istanbul-instrumenter-loader": "0.2.0",
"string-replace-webpack-plugin": "0.1.3",
"style-loader": "0.14.0",
## -81,9 +84,6 ##
"webpack-visualizer-plugin": "0.1.11",
"write-file-webpack-plugin": "3.4.2",
"xml2js": "0.4.17",
- "sass-loader": "5.0.1",
- "node-sass": "4.5.0",
- "postcss-loader": "1.3.0",
"yargs": "6.6.0"
},
"engines": {