appium/appium-ios-deviceの導入でつまづいた内容のまとめです。

環境

MacBookPro15 Mojave - macOS 10.14.6

事象

gulpが無いと言われたのでインスコへ

$ npm run watch

> appium-ios-device@1.2.1 watch /Users/gremito/git/appium-ios-device
> gulp watch

sh: gulp: command not found
npm ERR! code ELIFECYCLE
npm ERR! syscall spawn
npm ERR! file sh
npm ERR! errno ENOENT
npm ERR! appium-ios-device@1.2.1 watch: `gulp watch`
npm ERR! spawn ENOENT
npm ERR! 
npm ERR! Failed at the appium-ios-device@1.2.1 watch script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/gremito/.npm/_logs/2019-12-13T01_50_49_622Z-debug.log

`gulp`インストール

するとpermssion deniedでエラーになりました。

$ sudo npm install gulp -g
Password:
npm WARN deprecated fsevents@1.2.9: One of your dependencies needs to upgrade to fsevents v2: 1) Proper nodejs v10+ support 2) No more fetching binaries from AWS, smaller package size
/usr/local/bin/gulp -> /usr/local/lib/node_modules/gulp/bin/gulp.js

> fsevents@1.2.9 install /usr/local/lib/node_modules/gulp/node_modules/fsevents
> node install

node-pre-gyp WARN Using needle for node-pre-gyp https download 
node-pre-gyp WARN Pre-built binaries not installable for fsevents@1.2.9 and node@12.13.1 (node-v72 ABI, unknown) (falling back to source compile with node-gyp) 
node-pre-gyp WARN Hit error EACCES: permission denied, mkdir '/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib' 
gyp WARN EACCES current user ("nobody") does not have permission to access the dev dir "/Users/gremito/Library/Caches/node-gyp/12.13.1"
gyp WARN EACCES attempting to reinstall using temporary dev dir "/usr/local/lib/node_modules/gulp/node_modules/fsevents/.node-gyp"
gyp WARN install got an error, rolling back install
gyp WARN install got an error, rolling back install
gyp ERR! configure error 
gyp ERR! stack Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/gulp/node_modules/fsevents/.node-gyp'
gyp ERR! System Darwin 18.7.0
gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "configure" "--fallback-to-build" "--module=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64/fse.node" "--module_name=fse" "--module_path=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64" "--napi_version=5" "--node_abi_napi=napi" "--napi_build_version=0" "--node_napi_label=node-v72"
gyp ERR! cwd /usr/local/lib/node_modules/gulp/node_modules/fsevents
gyp ERR! node -v v12.13.1
gyp ERR! node-gyp -v v5.0.5
gyp ERR! not ok 
node-pre-gyp ERR! build error 
node-pre-gyp ERR! stack Error: Failed to execute '/usr/local/bin/node /usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js configure --fallback-to-build --module=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64/fse.node --module_name=fse --module_path=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64 --napi_version=5 --node_abi_napi=napi --napi_build_version=0 --node_napi_label=node-v72' (1)
node-pre-gyp ERR! stack     at ChildProcess.<anonymous> (/usr/local/lib/node_modules/gulp/node_modules/fsevents/node_modules/node-pre-gyp/lib/util/compile.js:83:29)
node-pre-gyp ERR! stack     at ChildProcess.emit (events.js:210:5)
node-pre-gyp ERR! stack     at maybeClose (internal/child_process.js:1021:16)
node-pre-gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:283:5)
node-pre-gyp ERR! System Darwin 18.7.0
node-pre-gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/gulp/node_modules/fsevents/node_modules/node-pre-gyp/bin/node-pre-gyp" "install" "--fallback-to-build"
node-pre-gyp ERR! cwd /usr/local/lib/node_modules/gulp/node_modules/fsevents
node-pre-gyp ERR! node -v v12.13.1
node-pre-gyp ERR! node-pre-gyp -v v0.12.0
node-pre-gyp ERR! not ok 
Failed to execute '/usr/local/bin/node /usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js configure --fallback-to-build --module=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64/fse.node --module_name=fse --module_path=/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64 --napi_version=5 --node_abi_napi=napi --napi_build_version=0 --node_napi_label=node-v72' (1)
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.9 (node_modules/gulp/node_modules/fsevents):
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.9 install: `node install`
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status 1

+ gulp@4.0.2
added 316 packages from 217 contributors in 8.129s

解決方法

エラー内容をググるとVuejs界隈でも似たような現象が起きていたようです。
Errors during install of vue-cli on Mac OSX #3402を参考に再度gulpをインストールすると正常に入りました。

$ sudo npm install -g gulp --unsafe-perm
npm WARN deprecated fsevents@1.2.9: One of your dependencies needs to upgrade to fsevents v2: 1) Proper nodejs v10+ support 2) No more fetching binaries from AWS, smaller package size
/usr/local/bin/gulp -> /usr/local/lib/node_modules/gulp/bin/gulp.js

> fsevents@1.2.9 install /usr/local/lib/node_modules/gulp/node_modules/fsevents
> node install

node-pre-gyp WARN Using needle for node-pre-gyp https download 
[fsevents] Success: "/usr/local/lib/node_modules/gulp/node_modules/fsevents/lib/binding/Release/node-v72-darwin-x64/fse.node" is installed via remote
+ gulp@4.0.2
added 68 packages from 33 contributors and updated 1 package in 5.836s