I am using Ubuntu 24.04.2 LTS and have tried to compile TeXpresso:
akira@akira:~/texpresso$ make texpresso-tonic
make -f Makefile.tectonic tectonic
make[1]: Entering directory '/home/akira/texpresso'
cd tectonic && cargo build --release --features external-harfbuzz
error: package `home v0.5.11` cannot be built because it requires rustc 1.81 or newer, while the currently active rustc version is 1.75.0
Either upgrade to rustc 1.81 or newer, or use
cargo update home@0.5.11 --precise ver
where `ver` is the latest version of `home` supporting rustc 1.75.0
make[1]: *** [Makefile.tectonic:11: tectonic] Error 101
make[1]: Leaving directory '/home/akira/texpresso'
make: *** [Makefile:55: texpresso-tonic] Error 2
As such, I have to update rustc 1.81. I have tried rustup update stable but to no avail
akira@akira:~/texpresso$ rustup update stable
Command 'rustup' not found, but can be installed with:
sudo snap install rustup # version 1.27.1, or
sudo apt install rustup # version 1.26.0-3
See 'snap info rustup' for additional versions.
akira@akira:~/texpresso$ which rustc
/usr/bin/rustc
Could you explain how to update rustc in my system?