Having a gdb session interfers with editing

[worikgh]

Emacs 30.0.50, updated packages, Raspberry Pi 4\

Reproduce:

Create a new rust project Open it (main.rs) in emacs Start gdb Try to enter a new line in main.rs Get error: user-error: Current buffer has no process

More details:

cd /tmp
cargo new test_issue
emacs -nw -q --load ~/emacs-rust-config/standalone.el /tmp/test_issue/src/main.rs
M-x gdb
rust-gdb
rust-gdb -i=mi ../target/debug/test_issue
b main
run
C-x b main.rs
<enter new line>