`rustup toolchain link` with special characters in the toolchain name causes panics

[majaha]

I found that using special characters in the rustup toolchain link command can cause panics:

matt@Matts-PC:~/rust$ rustup toolchain link "foo(bar)" ~/rust/build/host/stage0/
matt@Matts-PC:~/rust$ RUST_BACKTRACE=1 rustup toolchain list
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("unexpected character in pre-release identifier")', src/utils/utils.rs:549:83
stack backtrace:
   0: rust_begin_unwind
             at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:575:5
   1: core::panicking::panic_fmt
             at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/core/src/panicking.rs:64:14
   2: core::result::unwrap_failed
             at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/core/src/result.rs:1790:5
   3: rustup::utils::utils::toolchain_sort::special_version
   4: rustup::utils::utils::toolchain_sort::toolchain_sort_key
   5: alloc::slice::<impl [T]>::sort_by::{{closure}}
   6: rustup::config::Cfg::list_toolchains
   7: rustup::cli::rustup_mode::toolchain_list
   8: rustup::cli::rustup_mode::main
   9: rustup_init::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
matt@Matts-PC:~/rust$

I also got similar results with "foo#bar"

I'd assume the problem is that rustup toolchain link needs to sanitise it's input more thoroughly.

This was tested on rustup 1.26.0 (5af9b9484 2023-04-05)

[rami3l]

@majaha Thanks a lot for filing this issue!

Would you mind reproducing it again with RUST_BACKTRACE=full as suggested?

[majaha]

Yeah, no problem:

$ rustup toolchain link "foo(bar)" ~/rust/build/host/stage0/
$ RUST_BACKTRACE=full rustup toolchain list
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("unexpected character in pre-release identifier")', src/utils/utils.rs:549:83
stack backtrace:
   0:     0x55c6c7478c2c - std::backtrace_rs::backtrace::libunwind::trace::ha271a8a7e1f3d4ef
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x55c6c7478c2c - std::backtrace_rs::backtrace::trace_unsynchronized::h85739da0352c791a
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x55c6c7478c2c - std::sys_common::backtrace::_print_fmt::hbc6ebcfb2910b329
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x55c6c7478c2c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::he1c117e52d53614f
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x55c6c716653e - core::fmt::write::h25eb51b9526b8e0c
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/core/src/fmt/mod.rs:1213:17
   5:     0x55c6c744a014 - std::io::Write::write_fmt::ha9edec5fb1621933
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/io/mod.rs:1682:15
   6:     0x55c6c747bb4f - std::sys_common::backtrace::_print::hf8657cd429fc3452
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x55c6c747bb4f - std::sys_common::backtrace::print::h41b9b18ed86f86bd
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x55c6c747b74f - std::panicking::default_hook::{{closure}}::h22a91871f4454152
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:267:22
   9:     0x55c6c747b431 - std::panicking::default_hook::h21ddc36de0cd4ae7
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:286:9
  10:     0x55c6c747c51d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h6f7e3c94ecc52e2f
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/alloc/src/boxed.rs:2002:9
  11:     0x55c6c747c51d - std::panicking::rust_panic_with_hook::h5059419d6d59b3d0
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:692:13
  12:     0x55c6c747c2b4 - std::panicking::begin_panic_handler::{{closure}}::h0f383c291cd78343
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:579:13
  13:     0x55c6c747c21c - std::sys_common::backtrace::__rust_end_short_backtrace::h70ab22f2ad318cdd
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/sys_common/backtrace.rs:137:18
  14:     0x55c6c747c1f1 - rust_begin_unwind
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/std/src/panicking.rs:575:5
  15:     0x55c6c70c8532 - core::panicking::panic_fmt::hd1d46bcde3c61d72
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/core/src/panicking.rs:64:14
  16:     0x55c6c70c8992 - core::result::unwrap_failed::h456a23f68607268c
                               at /rustc/9eb3afe9ebe9c7d2b84b71002d44f4a0edac95e0/library/core/src/result.rs:1790:5
  17:     0x55c6c73e49b1 - rustup::utils::utils::toolchain_sort::special_version::hd419ea6dca271f28
  18:     0x55c6c73e4391 - rustup::utils::utils::toolchain_sort::toolchain_sort_key::hab6c2d84bf9d24ee
  19:     0x55c6c73e404c - alloc::slice::<impl [T]>::sort_by::{{closure}}::h26b8a5a5c3a19913
  20:     0x55c6c73e2aff - rustup::config::Cfg::list_toolchains::h1ae262539898d218
  21:     0x55c6c74047de - rustup::cli::rustup_mode::toolchain_list::h23cda12eea14309e
  22:     0x55c6c73f0000 - rustup::cli::rustup_mode::main::h6982c861a7b9cf8f
  23:     0x55c6c70ee37c - rustup_init::main::hfde47befa0e5797c
  24:     0x55c6c70ec4d3 - std::sys_common::backtrace::__rust_begin_short_backtrace::h747e7fed170da8a9
  25:     0x55c6c70eed39 - main
  26:     0x7f0005aedd90 - __libc_start_call_main
                               at ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
  27:     0x7f0005aede40 - __libc_start_main_impl
                               at ./csu/../csu/libc-start.c:392:3
  28:     0x55c6c70ec40b - <unknown>
  29:                0x0 - <unknown>

[rami3l]

@majaha Thanks! The cause of this issue is the following hack:

rustup/src/toolchain/names.rs

Lines 311 to 343 in b5d74ac

	pub(crate) fn toolchain_sort(v: &mut [ToolchainName]) {
	use semver::{BuildMetadata, Prerelease, Version};
	fn special_version(ord: u64, s: &str) -> Version {
	Version {
	major: 0,
	minor: 0,
	patch: 0,
	pre: Prerelease::new(&format!("pre.{}.{}", ord, s.replace('_', "-"))).unwrap(),
	build: BuildMetadata::EMPTY,
	}
	}
	fn toolchain_sort_key(s: &str) -> Version {
	if s.starts_with("stable") {
	special_version(0, s)
	} else if s.starts_with("beta") {
	special_version(1, s)
	} else if s.starts_with("nightly") {
	special_version(2, s)
	} else {
	Version::parse(&s.replace('_', "-")).unwrap_or_else(|_| special_version(3, s))
	}
	}
	v.sort_by(|a, b| {
	let a_str = &format!("{a}");
	let b_str = &format!("{b}");
	let a_key = toolchain_sort_key(a_str);
	let b_key = toolchain_sort_key(b_str);
	a_key.cmp(&b_key)
	});
	}

I'll claim this and fix it soon. Stay tuned!