Panic when vendoring remote modules containing npm specifiers

[jespertheend]

To reproduce

1. Run the following command:deno vendor https://gist.githubusercontent.com/jespertheend/6f05a6c8ce082dcb976740db8e9232e7/raw/577685d2c8506d1d4d27d5fa2f6ddb5c1ffd4c54/import_npm_specifier.js.

Which is a file that contains only: import "npm:[email protected]";

============================================================
Deno has panicked. This is a bug in Deno. Please report this
at https://github.com/denoland/deno/issues/new.
If you can reliably reproduce this panic, include the
reproduction steps and re-run with the RUST_BACKTRACE=1 env
var set and include the backtrace in your report.

Platform: macos x86_64
Version: 1.29.1
Args: ["deno", "vendor", "https://gist.githubusercontent.com/jespertheend/6f05a6c8ce082dcb976740db8e9232e7/raw/577685d2c8506d1d4d27d5fa2f6ddb5c1ffd4c54/import_npm_specifier.js"]

thread 'main' panicked at 'Could not find local path for npm:[email protected]', cli/tools/vendor/mappings.rs:138:11
stack backtrace:
   0:        0x10a2ddeb7 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd2e8cbde22b780fc
   1:        0x1097a17fa - core::fmt::write::hd6692086cdd356a7
   2:        0x10a2acfac - std::io::Write::write_fmt::h6043124a2486acbb
   3:        0x10a2e2cab - std::panicking::default_hook::{{closure}}::h87a12b8b06887dd7
   4:        0x10a2e2973 - std::panicking::default_hook::h7f68dad17e0bfaa4
   5:        0x1096e2f50 - deno::setup_panic_hook::{{closure}}::h3c2f685e7d6b3aa1
   6:        0x10a2e3218 - std::panicking::rust_panic_with_hook::hd57427cbbfc3717a
   7:        0x10a2e2fe4 - std::panicking::begin_panic_handler::{{closure}}::h33aab6d04e2bba70
   8:        0x10a2e2f48 - std::sys_common::backtrace::__rust_end_short_backtrace::h0e7a76f927db9964
   9:        0x10a2e2f12 - _rust_begin_unwind
  10:        0x10b6e2ba3 - core::panicking::panic_fmt::hcf6f3c517c6f3cb3
  11:        0x1096bab89 - deno::tools::vendor::mappings::Mappings::local_path::hf942d439a0f2e7e7
  12:        0x1096ba9cf - deno::tools::vendor::mappings::Mappings::local_uri::h158514494ca09a71
  13:        0x1096babc0 - deno::tools::vendor::mappings::Mappings::relative_specifier_text::h597cd74bf0854bb9
  14:        0x1096b9977 - deno::tools::vendor::import_map::ImportsBuilder::add::h4ae1472cbec50ded
  15:        0x1096ba656 - deno::tools::vendor::import_map::visit_maybe_resolved::h9f11ab6ef7b6a8a9
  16:        0x1096b75d7 - deno::tools::vendor::build::build::ha2b59e1a6a87ebe1
  17:        0x1096d48d7 - deno::run_subcommand::{{closure}}::he6be3ac4aee88a96
  18:        0x1096e76f8 - deno::main::{{closure}}::h48c8ed1535d860ab
  19:        0x109526f9d - <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h6ea21c59ce307865
  20:        0x1093711d5 - deno_runtime::tokio_util::run_local::h83b195a4ae96ef32
  21:        0x1096e322c - deno::main::hdfc9a952d3e6dfae
  22:        0x1093a9db1 - std::sys_common::backtrace::__rust_begin_short_backtrace::h3bd53d04eab25172
  23:        0x109731622 - _main

[evelant]

Also running into this I think. I'm having a heck of a frustrating time trying to use Deno migrating my firebase cloud functions to supabase edge functions. Roadblocks at every turn. Every time I think I've worked around one thing I run into another. ☹️

This time I tried to work around problems importing local packages from my pnpm workspace by vendoring them directly from a private github repo, only to run into this panic.

[jespertheend]

Remote modules with npm specifiers require the --unstable flag. That's why this hasn't received much attention yet I believe.