I used the dumpbin tool to examine my caffe2_detectron_ops_gpu.dll, which only has a size of ~5.5MB.
With the EXPORTS option, the results are as follows:
Microsoft (R) COFF/PE Dumper Version 14.00.24215.1
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file D:\repo\github\pytorch\build\bin\Release\caffe2_detectron_ops_gpu.dll

File Type: DLL

  Section contains the following exports for caffe2_detectron_ops_gpu.dll

    00000000 characteristics
    5B0CBE13 time date stamp Tue May 29 10:42:27 2018
        0.00 version
           1 ordinal base
           1 number of functions
           1 number of names

    ordinal hint RVA      name

          1    0 003393E8 NvOptimusEnablementCuda

  Summary

       13000 .data
        1000 .gfids
        1000 .nvFatBi
      20C000 .nv_fatb
       23000 .pdata
       E6000 .rdata
        5000 .reloc
        1000 .rsrc
      252000 .text
        1000 .tls

With the SYMBOLS option, the results are as follows:
Microsoft (R) COFF/PE Dumper Version 14.00.24215.1
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file D:\repo\github\pytorch\build\bin\Release\caffe2_detectron_ops_gpu.dll

File Type: DLL

  Summary

       13000 .data
        1000 .gfids
        1000 .nvFatBi
      20C000 .nv_fatb
       23000 .pdata
       E6000 .rdata
        5000 .reloc
        1000 .rsrc
      252000 .text
        1000 .tls

Does this mean the Detectron operators are actually not compiled? If so, what could possibly be the reason and how can I make them compile?