Disable any cert check on localhost on chrome

Question

I just tried to work, but Google works very hard to prevent me to do so. I just wanted to develop my favourite legacy application witch I have to use with HTTPS even during development time on localhost. I set up everything just like I do for a long time now... But suddenly I started to get NET::ERR_CERT_INVALID error.

I added the cert to my keychain and set it to trust always.

I checked the setting in Chrome that I know and set a long time ago, that allows me to use self-signed certs on localhost:

chrome://flags/#allow-insecure-localhost

But now I can't find it. Is it possible they removed it? I also tried to start chrome from the command line with the following parameters:

Google\ Chrome.app/Contents/MacOS/Google\ Chrome  --ignore-certificate-errors --ignore-urlfetcher-cert-requests &> /dev/null

But with this, I also get NET::ERR_CERT_INVALID error. I tried both the flag and command line option with the following versions of Chrome:

88.0.4324.96 (Official Build) (x86_64)
90.0.4394.0 (Official Build) canary (x86_64)

Answer 1

The flag allow-insecure-localhost seems to no longer be available on Chrome 88 (apparently flags expire after a certain amount of time) and should be back with v89, according to this: https://bugs.chromium.org/p/chromium/issues/detail?id=1159077