I've installed rust. By default book is installed at
file:///home/< user name >/snap/rustup/common/rustup/toolchains/stable-x86_64-unknown-linux-gnu/share/doc/rust/html/book/index.html
Unable to open it in browser.
It will be nice if you install the book at standard location /usr/share/doc
If you want to install rustup and its components in more standard paths, you could consider removing the snap and using the standard installation instead. Though that also puts it into a folder in the user directory (/home/<user name>/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/share/doc/rust/html/book/index.html) so I’m not certain whether that would make a significant difference for your problems.
Regarding the problem at hand, what’s the output of rustup doc for you? What kind of errors / problems are you encountering? I’m personally not too familiar with snaps though, but perhaps others can help.
If the actual problem is a firefox snap being unable to read the files, and if you happen to have google-chrome installed as a non-snap with proper file access, but firefox is the default browser, then you could also see if something like executing BROWSER="google-chrome" rustup doc works.
rustup doc ...
this file is also not accessible
file:///home/< user name >/snap/rustup/common/rustup/toolchains/stable-x86_64-unknown-linux-gnu/share/doc/rust/html/index.html
both firefox & chrome are installed using snap.
to install firefox without snap, I have to do
sudo add-apt-repository ppa:mozillateam/ppa
but this command is hanging for quite long time and terminating with timeout error.
Irrespective of snap, default location shouldn't have been gone to snap folder.
Question is, how did you installed rustup in the first place? Using the standard installation script, it should appear under $HOME/.rustup, not $HOME/snap.
Installing google-chrome without a snap is fairly simply in my experience. Given all browsers you tried are snaps, that might be the problem. AFAIR, there’s some problems with opening files from the local file system in browsers installed via snaps (at least for firefox I’ve heard of that problem) due to the sandboxing.
I would assume possible via this snap?, though reading the description
NOTA BENE: This is an experimental, unofficial, snap and should not be relied on.
it might be a good idea to switch to the official rustup installation procedure anyways. Unless that warning is just overly cautious; maybe there’s nothing wrong with that snap, I honestly don’t know; if nothing else, one upside of using the standard installation procedure is that if any trouble comes up, it’s easier to ask for help if you’re doing the same everyone else does.
sudo snap install rustup