gritty: Installation error

I’m trying to build with cloudcmd and gritty, but I always get an error, according to the log:

2310 verbose stack Exit status 1
2310 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:332:16)
2310 verbose stack     at EventEmitter.emit (events.js:315:20)
2310 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
2310 verbose stack     at ChildProcess.emit (events.js:315:20)
2310 verbose stack     at maybeClose (internal/child_process.js:1048:16)
2310 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:288:5)
2311 verbose pkgid node-pty@0.10.0
2312 verbose cwd /var/www/html
2313 verbose Linux 4.19.0-14-amd64
2314 verbose argv "/usr/bin/node" "/usr/bin/npm" "i" "gritty" "-g"
2315 verbose node v14.16.1
2316 verbose npm  v6.14.12
2317 error code ELIFECYCLE
2318 error errno 1
2319 error node-pty@0.10.0 install: `node scripts/install.js`
2319 error Exit status 1
2320 error Failed at the node-pty@0.10.0 install script.
2320 error This is probably not a problem with npm. There is likely additional logging output above.
2321 verbose exit [ 1, true ]

Cloudcmd has already been installed using NPM and is running normally.