same problem
either with debian 10.
I can confirm the same issue on Ubuntu 18.04.
I am also fairly sure of the actual problem that has nothing to do with the OS.
It seams that someone has changed file permissions on https://dl.bintray.com/etcher/debian/dists/stable/ such that the files Release and Release.gpg are not readable by the web server. So the files are present but since the server sends 403 then the package manager just tells you that they are missing.
Solution: Could the person managing the server make these two files readable to the web server?
Same issue with Fedora (rpm based distro):
$ sudo dnf update etcher
etcher-rpm 21 B/s | 10 B 00:00
Errors during downloading metadata for repository 'etcher-rpm':
Status code: 403 for https://dl.bintray.com/etcher/redhat/repodata/repomd.xml (IP: 52.28.187.224)
Error: Failed to download metadata for repo 'etcher-rpm': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
Ignoring repositories: etcher-rpm
Same on Pop!_OS 19.10
There is already an issue for this problem: #3078.
They say they are working on it - https://github.com/balena-io/etcher/issues/3078#issuecomment-590819461
You can subscribe to that issue and wait for an update.
Would be cool if they pinned the original issue to prevent dupes
As mentioned by @etchichury , please follow the other issue, thanks for the patience
Most helpful comment
I can confirm the same issue on Ubuntu 18.04.
I am also fairly sure of the actual problem that has nothing to do with the OS.
It seams that someone has changed file permissions on https://dl.bintray.com/etcher/debian/dists/stable/ such that the files Release and Release.gpg are not readable by the web server. So the files are present but since the server sends 403 then the package manager just tells you that they are missing.
Solution: Could the person managing the server make these two files readable to the web server?