emily: this is my build env info, I failed to build aiohttp python package due to too many open files, unless I added NIX_BUILD_CORES=2:

kdn@oams ~> TERM=xterm ssh anji
Last login: Fri Dec 19 14:50:23 2025 from 100.79.80.79
kdn@anji:~/ > nom build 'nixpkgs#tests.build-environment-info'
this derivation will be built:
  /nix/store/qrz6qkidl71gmf19abzah4a3vvdx20gx-build-environment-info.drv
build-environment-info> building '/nix/store/qrz6qkidl71gmf19abzah4a3vvdx20gx-build-environment-info.drv'
build-environment-info> :: uname -a
build-environment-info> Darwin anji 25.0.0 Darwin Kernel Version 25.0.0: Mon Aug 25 21:17:53 PDT 2025; root:xnu-12377.1.9~3/RELEASE_ARM64_T8112 arm64 arm Darwin
build-environment-info> :: env SYSTEM_VERSION_COMPAT=0 plutil -p /System/Library/CoreServices/SystemVersion.plist
build-environment-info> {
build-environment-info> 	BuildID = "6E524054-8D44-11F0-A95E-B45191F12EA9";
build-environment-info> 	ProductBuildVersion = 25A354;
build-environment-info> 	ProductCopyright = "1983-2025 Apple Inc.";
build-environment-info> 	ProductName = macOS;
build-environment-info> 	ProductUserVisibleVersion = "26.0";
build-environment-info> 	ProductVersion = "26.0";
build-environment-info> 	iOSSupportVersion = "26.0";
build-environment-info> }
build-environment-info> :: id
build-environment-info> uid=351(_nixbld1) gid=350(nixbld) groups=350(nixbld)
build-environment-info> :: getent passwd _nixbld1
build-environment-info> _nixbld1:********:351:350:Nix build user 1:/var/empty:/sbin/nologin
build-environment-info> :: ulimit -a
build-environment-info> core file size              (blocks, -c) 0
build-environment-info> data seg size               (kbytes, -d) unlimited
build-environment-info> file size                   (blocks, -f) unlimited
build-environment-info> max locked memory           (kbytes, -l) unlimited
build-environment-info> max memory size             (kbytes, -m) unlimited
build-environment-info> open files                          (-n) 1048576
build-environment-info> pipe size                (512 bytes, -p) 1
build-environment-info> stack size                  (kbytes, -s) 65520
build-environment-info> cpu time                   (seconds, -t) unlimited
build-environment-info> max user processes                  (-u) 2666
build-environment-info> virtual memory              (kbytes, -v) unlimited
build-environment-info> :: exit 1