_GNU_SOURCE redefined

[kczulko]

Hello,

While working on rules_nim I've noticed the following redefinition

Nim/lib/pure/strutils.nim

Line 2011 in 86d6f71

needle: pointer, needlelen: csize_t): pointer {.importc, header: """#define _GNU_SOURCE

in the build output log:

INFO: From Compiling src/rules_nim_nimble_gen_cc_files_only/@m..@s..@s..@s..@sexternal@srules_nim~~nim~nim_linux_x64@slib@spure@sstrutils.nim.c:
bazel-out/k8-fastbuild/bin/src/rules_nim_nimble_gen_cc_files_only/@m..@s..@s..@s..@sexternal@srules_nim~~nim~nim_linux_x64@slib@spure@sstrutils.nim.c:6: warning: "_GNU_SOURCE" redefined
    6 | #define _GNU_SOURCE
      |
In file included from bazel-out/k8-fastbuild/bin/src/rules_nim_nimble_gen_cc_files_only/@m..@s..@s..@s..@sexternal@srules_nim~~nim~nim_linux_x64@slib@spure@sstrutils.nim.c:4:
external/rules_nim~~nim~nim_linux_x64/lib/nimbase.h:78: note: this is the location of the previous definition
   78 | #  define _GNU_SOURCE 1
      |

Can I add #ifndef around it?

Best regards,
Karol