nix eval segmentation fault on long line (`nix eval nixpkgs#legacyPackages`)

[hraban]

Describe the bug

Nix tool segfaults when printing a large set.

Steps to reproduce

$ nix eval  nixpkgs#lispPackages_new.sbclPackages
Segmentation fault: 11

Another example:

$ nix repl
(import <nixpkgs> {}).lispPackages_new.sbclPackages

... outputs a lot, then:

Segmentation fault: 11
$

Same if I clone nixpkgs locally and do import ./. {}, instead.

Expected behavior

A very very long output line.

Metadata

$ nix-env --version
nix-env (Nix) 2.9.1
$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-darwin"`
 - host os: `Darwin 21.6.0, macOS 10.16`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.9.1`
 - channels(hraban): `""`
 - channels(root): `"nixpkgs"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixpkgs`

Additional context

Originally posted to NixOS/nixpkgs#190092

[hraban]

Update:

Some segfaults persist, some are solved.

The title operation still causes a segfault:

$ nix eval nixpkgs#legacyPackages
Segmentation fault: 11

However, these do not cause segfaults anymore:

$ nix repl
> (import <nixpkgs> {}).lispPackages_new.sbclPackages
... long output but survives
> import <nixpkgs> {}
... again long output and survives

Version:

$ nix-env --version
nix-env (Nix) 2.12.0
$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-darwin"`
 - host os: `Darwin 21.6.0, macOS 10.16`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.12.0`
 - channels(hraban): `"darwin"`
 - channels(root): `"nixpkgs"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixpkgs`