Why does process.env.PUBLIC_URL === "" in dev mode (localhost)?

[devuxer]

Given that #7259 was merged, I can't figure out why the PUBLIC_URL in my .env file is seemingly being ignored.

Any use of process.env.PUBLIC_URL in my JS/TS code (e.g., TSX files) shows up as an empty string.

My .env file is in the root level of my project.

The entry in my .env file looks like this:

PUBLIC_URL=http://localhost:3000

Note that when I'm testing this, I restart the dev server using react-scripts start.

According to the docs:

Apart from a few built-in variables (NODE_ENV and PUBLIC_URL), variable names must start with REACT_APP_ to work.

I read this to mean what I'm trying to do should work, but maybe I'm misunderstanding.

Am I looking at a CRA bug or doing something wrong?

[gavenkoa]

Try to specify it explicitly via command line, like:

PUBLIC_URL=http://localhost:3000 react-scripts start

May be .env isn't picked out...

[biserz]

The solution here addressed an identical issue for me #12455 (comment)