Jest cannot find module in workspace - npm

Question

I have an NPM project structured in workspaces:
proj/
+-node_modules/
+-packages/
+-pkg1/
+-src/
|-c1.ts
|-c1.test.ts
|-package.json
|-jest.config.js
+-pkg2/
+-src/
|-c2.ts
|-package.json
+-apps/
|-package.json
The project's package.json:
{
"name": "proj",
"scripts": {
...
"test:pkg1": "npm test -w packages/pkg1",
},
"workspaces": [
"packages/*",
"apps/*"
]
}
The package.json inside pkg1:
{
"name": "#proj/pkg1",
"scripts": {
...
"test": "jest --config=jest.config.js",
},
"devDependencies": {
"#types/pegjs": "0.10.3",
"#types/jest": "29.1.1",
"ts-loader": "9.3.1",
"typescript": "4.8.3",
"webpack": "5.74.0",
"webpack-cli": "4.10.0",
"jest": "29.1.2",
"ts-jest": "29.0.3"
},
"dependencies": {
"#proj/pkg2": "1.0.0"
}
}
The test file c1.test.ts is:
import { Component1 } from "#proj/pkg2";
describe("some tests", () => {
test("a test case", () => {
// Arrange ...
// Act ...
// Assert ...
});
});
The problem
When, from the project's root, I run: npm run test:pkg1, I get:
> 1 | import { Component1 } from "#proj/pkg2";
| ^
3 | describe("some tests", () => {
4 | test("a test case", () => {
5 | // Arrange
at Resolver._throwModNotFoundError (../../node_modules/jest-resolve/build/resolver.js:487:11)
Jest cannot find "#proj/pkg2". It makes sense as it cannot understand workspaces and Jest compiles all files before running the tests. How to solve this?