Build broken in nix-shell due to linker errors

[blitz]

I'm trying to build nix in a nix-shell on Fedora 31, but the linking step eventually fails with undefined references to __clock_nanosleep@GLIBC_PRIVATE (and similar):

% nix-shell --pure
nix-shell % sh bootstrap.sh
[...]
nix-shell % configure && make -j4
[...]

  LD     src/libstore/libnixstore.so
  LD     src/libexpr/libnixexpr.so
  LD     src/libmain/libnixmain.so
  LD     src/nix/nix
/nix/store/7wy2mifb0igrp9hzf9dzwddadbs7ai7d-binutils-2.31.1/bin/ld: /nix/store/sc7lh1dhvd7fg28d7dxwsqzfcinnr6j5-glibc-2.30/lib/librt.so.1: undefined reference to `__clock_nanosleep@GLIBC_PRIVATE'
/nix/store/7wy2mifb0igrp9hzf9dzwddadbs7ai7d-binutils-2.31.1/bin/ld: /nix/store/sc7lh1dhvd7fg28d7dxwsqzfcinnr6j5-glibc-2.30/lib/librt.so.1: undefined reference to `__clock_getres@GLIBC_PRIVATE'
/nix/store/7wy2mifb0igrp9hzf9dzwddadbs7ai7d-binutils-2.31.1/bin/ld: /nix/store/sc7lh1dhvd7fg28d7dxwsqzfcinnr6j5-glibc-2.30/lib/librt.so.1: undefined reference to `__clock_getcpuclockid@GLIBC_PRIVATE'
/nix/store/7wy2mifb0igrp9hzf9dzwddadbs7ai7d-binutils-2.31.1/bin/ld: /nix/store/sc7lh1dhvd7fg28d7dxwsqzfcinnr6j5-glibc-2.30/lib/librt.so.1: undefined reference to `__clock_settime@GLIBC_PRIVATE'
collect2: error: ld returned 1 exit status
make: *** [mk/lib.mk:105: src/nix/nix] Error 1

[blitz]

This does not reproduce on NixOS, which suggests that there is some impurity in the nix-shell --pure. Any pointers are appreciated.

[domenkozar]

The impurity is glibc. See NixOS/nixpkgs#84043 for an example.