I was not sure, if I should open a new topic or just add another comment to the previous topic. I think we should have a process for that. 
Anyway, I pulled the latest changes (dev 3ecf942b4) a few minutes ago and this is what happens:
@joplin/tools: > @joplin/tools@1.7.3 tsc /Users/tessus/data/work/joplin/packages/tools
@joplin/tools: > tsc --project tsconfig.json
joplin: tests/services/plugins/RepositoryApi.ts(7,13): error TS2339: Property 'loadManifests' does not exist on type 'RepositoryApi'.
joplin: tests/services/plugins/RepositoryApi.ts(21,31): error TS2341: Property 'manifests' is private and only accessible within class 'RepositoryApi'.
joplin: tests/services/plugins/RepositoryApi.ts(51,20): error TS2339: Property 'pluginCanBeUpdated' does not exist on type 'RepositoryApi'.
joplin: tests/services/plugins/RepositoryApi.ts(52,20): error TS2339: Property 'pluginCanBeUpdated' does not exist on type 'RepositoryApi'.
joplin: tests/services/plugins/RepositoryApi.ts(53,20): error TS2339: Property 'pluginCanBeUpdated' does not exist on type 'RepositoryApi'.
joplin: tests/test-utils.ts(19,25): error TS7016: Could not find a declaration file for module '@joplin/lib/onedrive-api'. '/Users/tessus/data/work/joplin/packages/app-cli/node_modules/@joplin/lib/onedrive-api.js' implicitly has an 'any' type.
joplin: Try `npm install @types/joplin__lib` if it exists or add a new declaration (.d.ts) file containing `declare module '@joplin/lib/onedrive-api';`
joplin: tests/test-utils.ts(20,32): error TS7016: Could not find a declaration file for module '@joplin/lib/SyncTargetOneDrive'. '/Users/tessus/data/work/joplin/packages/app-cli/node_modules/@joplin/lib/SyncTargetOneDrive.js' implicitly has an 'any' type.
joplin: Try `npm install @types/joplin__lib` if it exists or add a new declaration (.d.ts) file containing `declare module '@joplin/lib/SyncTargetOneDrive';`
joplin: npm ERR! code ELIFECYCLE
joplin: npm ERR! errno 2
joplin: npm ERR! joplin@1.7.0 tsc: `node node_modules/typescript/bin/tsc --project tsconfig.json`
joplin: npm ERR! Exit status 2
joplin: npm ERR!
joplin: npm ERR! Failed at the joplin@1.7.0 tsc script.
joplin: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
joplin: npm ERR! A complete log of this run can be found in:
joplin: npm ERR! /Users/tessus/.npm/_logs/2021-01-21T15_03_55_242Z-debug.log
lerna ERR! npm run tsc exited 2 in 'joplin'
lerna WARN complete Waiting for 2 child processes to exit. CTRL-C to exit immediately.
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! root@ tsc: `lerna run tsc --stream --parallel`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the root@ tsc script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/tessus/.npm/_logs/2021-01-21T15_03_55_303Z-debug.log
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! root@ build: `lerna run build && npm run tsc`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the root@ build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/tessus/.npm/_logs/2021-01-21T15_03_55_342Z-debug.log
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! root@ postinstall: `npm run bootstrap --no-ci && npm run build`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the root@ postinstall script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
Update: This also happens in the ci pipeline.