pkg/56507: hgrep fails to build with stable rust

[nia%pkgsrc.org@localhost]

>Number:         56507
>Category:       pkg
>Synopsis:       hgrep fails to build with stable rust
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 18 13:35:00 +0000 2021
>Originator:     nia
>Release:        current
>Organization:
The NetBSD Foundation
>Environment:
>Description:
=> Bootstrap dependency digest>=20211023: found digest-20211023
===> Skipping vulnerability checks.
WARNING: No /usr/pkg/pkgdb/pkg-vulnerabilities file found.
WARNING: To fix run: `/usr/sbin/pkg_admin -K /usr/pkg/pkgdb fetch-pkg-vulnerabilities'.
===> Building for hgrep-0.2.1
warning: Both `/tmp/work/textproc/hgrep/work/hgrep-0.2.1/.cargo/config` and `/tmp/work/textproc/hgrep/work/hgrep-0.2.1/.cargo/config.toml` exist. Using `/tmp/work/textproc/hgrep/work/hgrep-0.2.1/.cargo/config`
error: failed to load manifest for workspace member `/tmp/work/textproc/hgrep/work/hgrep-0.2.1/assets/builder`

Caused by:
  failed to parse manifest at `/tmp/work/textproc/hgrep/work/hgrep-0.2.1/assets/builder/Cargo.toml`

Caused by:
  feature `edition2021` is required

  this Cargo does not support nightly features, but if you
  switch to nightly channel you can add
  `cargo-features = ["edition2021"]` to enable this feature
*** Error code 101

Stop.
make[1]: stopped in /usr/pkgsrc/textproc/hgrep
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/textproc/hgrep

>How-To-Repeat:

>Fix:
Downgrade hgrep?