docs: add gotcha for yarn timeout (#30)

Author: varl

2019/01/21.md renamed to decisions/2019/01/21.md

@@ -0,0 +1,67 @@
+When running `yarn install` in projects which depend on very large packages Yarn hits the timeout limit and eventually throws the error `ESOCKETTIMEDOUT`.
+
+```sh
+yarn install
+
+yarn install v1.13.0
+[1/4] Resolving packages...
+[2/4] Fetching packages...
+info There appears to be trouble with your network connection. Retrying...
+info There appears to be trouble with your network connection. Retrying...
+info There appears to be trouble with your network connection. Retrying...
+info There appears to be trouble with your network connection. Retrying...
+error An unexpected error occurred: "<some package name>: ESOCKETTIMEDOUT".
+info If you think this is a bug, please open a bug report with the information provided in "/home/varl/dev/dhis2/apps/dashboards-app/yarn-error.log".
+info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
+```
+
+## Troubleshooting
+
+It is helpful to run the `yarn install` command with the `--verbose` switch to get additional information as well.
+
+```sh
+yarn install --verbose
+
+yarn install v1.13.0
+verbose 0.568 Found configuration file "/home/varl/.yarnrc".
+verbose 0.568 Checking for configuration file "/home/.yarnrc".
+verbose 0.572 current time: 2019-03-15T07:25:03.674Z
+[1/4] Resolving packages...
+[2/4] Fetching packages...
+verbose 13.542 Performing "GET" request to "https://registry.yarnpkg.com/material-ui/-/material-ui-0.20.2.tgz".
+info There appears to be trouble with your network connection. Retrying...
+verbose 13.638 Error: https://registry.yarnpkg.com/@dhis2/d2-i18n/-/d2-i18n-1.0.4.tgz: ESOCKETTIMEDOUT
+    at ClientRequest.<anonymous> (/usr/share/yarn/lib/cli.js:130024:19)
+    at Object.onceWrapper (events.js:277:13)
+    at ClientRequest.emit (events.js:189:13)
+    at TLSSocket.emitRequestTimeout (_http_client.js:662:40)
+    at Object.onceWrapper (events.js:277:13)
+    at TLSSocket.emit (events.js:189:13)
+    at TLSSocket.Socket._onTimeout (net.js:443:8)
+    at ontimeout (timers.js:436:11)
+    at tryOnTimeout (timers.js:300:5)
+    at listOnTimeout (timers.js:263:5)
+error An unexpected error occurred: "https://registry.yarnpkg.com/@dhis2/d2-i18n/-/d2-i18n-1.0.4.tgz: ESOCKETTIMEDOUT".
+info If you think this is a bug, please open a bug report with the information provided in "/home/varl/dev/dhis2/apps/dashboards-app/yarn-error.log".
+info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
+```
+
+## Solution
+
+Increasing the `network-timeout` for Yarn is one way to fix it. You can choose to increase the limit globally or per-project. I did it globally in the example below. The configuration option accepts milliseconds. Here I set it to 10 minutes for _**OVERKILL**_ 😎.
+
+```sh
+yarn config set network-timeout 600000 -g
+
+yarn config v1.13.0
+success Set "network-timeout" to "600000".
+Done in 0.04s.
+```
+
+## Bonus solution
+
+The only package I've seen this problem on is the [`material-design-icons`](https://www.npmjs.com/package/material-design-icons) package which has a ridiculous amount of files in a large package format. If you only need the iconfont, the [`material-design-icons-iconfont`](https://github.com/Jossef/material-design-icons-iconfont) works as a drop-in replacement and is a lot smaller (package-wise).
+
+## Discussion
+
+- [dhis2/notes](https://github.com/dhis2/notes/issues/29)