pydicom fail in test

[tfmoraes]

Issue description

Pydicom is failing to build because of a fail in test. The error:

builder for '/nix/store/rs04xq2kid4akvdd9x2kb22lvrjfrz0n-python3.8-pydicom-2.1.1.drv' failed with exit code 1; last 10 log lines:
  ERROR pydicom/tests/test_gdcm_pixel_data.py::TestGDCM_JPEGlossless_no_gdcm::testJPEGlossless_pixel_array
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_no_jpeg_ls::test_JPEG_LS_PixelArray
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEG2000_no_jpeg_ls::test_JPEG2000PixelArray
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEG2000_no_jpeg_ls::test_emri_JPEG2000PixelArray
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEGlossy_no_jpeg_ls::testJPEGlossy
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEGlossy_no_jpeg_ls::testJPEGlossyPixelArray
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEGlossy_no_jpeg_ls::testJPEGBaselineColor3DPixelArray
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEGlossless_no_jpeg_ls::testJPEGlossless
  ERROR pydicom/tests/test_jpeg_ls_pixel_data.py::TestJPEGLS_JPEGlossless_no_jpeg_ls::testJPEGlosslessPixelArray
  = 177 failed, 1660 passed, 236 skipped, 1 deselected, 2 xfailed, 72 warnings, 29 errors in 54.97s =

Steps to reproduce

Add pydicom in your system packages.

Technical details

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

❯ nix-shell -p nix-info --run "nix-info -m"                                                                                                                     
this path will be fetched (0.00 MiB download, 0.00 MiB unpacked):
  /nix/store/nmzhi83mai0ckfkm9hwawal95hvb2mdd-nix-info
copying path '/nix/store/nmzhi83mai0ckfkm9hwawal95hvb2mdd-nix-info' from 'https://cache.nixos.org'...
 - system: `"x86_64-linux"`
 - host os: `Linux 5.8.18, NixOS, 21.03.20201203.2967936 (Okapi)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.4pre20201201_5a6ddb3`
 - channels(root): `"nixos-21.03pre250162.34ad166a830"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`