import fiona result in ImportError: DLL load failed... in conda env, while a virtualenv works

Question

I have looked for information online but cannot find anything relevant to this specific issue.

When importing fiona while using a conda environment, I get the following stacktrace:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Nick\anaconda3\envs\general\Lib\site-packages\fiona\__init__.py", line 41, in <module>
    from fiona._env import (
ImportError: DLL load failed while importing _env: The specified procedure could not be found.

similarly, when I run fio in a terminal I get this message:

Traceback (most recent call last):
  File "C:\Users\Nick\anaconda3\envs\general\Scripts\fio-script.py", line 6, in <module>
    from fiona.fio.main import main_group
  File "C:\Users\Nick\anaconda3\envs\general\Lib\site-packages\fiona\__init__.py", line 41, in <module>
    from fiona._env import (
ImportError: DLL load failed while importing _env: The specified procedure could not be found.

I can however successfully import fiona if I use a fresh virtualenv venv that I made to test. This works for now for the script I'm working on, but it not a permanent solution as I cannot get gdal to work via installation from pip, I have only been able to get it working by using conda install -c conda-forge gdal. I know eventually I will need to use both gdal and fiona in the same script so I am looking for a solution before that happens.

---

Below is the process used to create a new conda environment and install python and fiona, then trying to import fiona using that env.

Nick@w11-virt-nh MINGW64 ~/Desktop/scratch
$ conda create -n fionatest python fiona
Collecting package metadata (current_repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: C:\Users\Nick\anaconda3\envs\fionatest

  added / updated specs:
    - fiona
    - python


The following NEW packages will be INSTALLED:

  attrs              conda-forge/noarch::attrs-23.1.0-pyh71513ae_1
  blosc              conda-forge/win-64::blosc-1.21.5-hdccc3a2_0
  bzip2              conda-forge/win-64::bzip2-1.0.8-h8ffe710_4
  ca-certificates    conda-forge/win-64::ca-certificates-2023.7.22-h56e8100_0
  cairo              conda-forge/win-64::cairo-1.18.0-h1fef639_0
  cfitsio            conda-forge/win-64::cfitsio-4.3.0-h9b0cee5_0
  click              conda-forge/noarch::click-8.1.7-win_pyh7428d3b_0
  click-plugins      conda-forge/noarch::click-plugins-1.1.1-py_0
  cligj              conda-forge/noarch::cligj-0.7.2-pyhd8ed1ab_1
  colorama           conda-forge/noarch::colorama-0.4.6-pyhd8ed1ab_0
  expat              conda-forge/win-64::expat-2.5.0-h63175ca_1
  fiona              conda-forge/win-64::fiona-1.9.5-py312he9aeaab_0
  font-ttf-dejavu-s~ conda-forge/noarch::font-ttf-dejavu-sans-mono-2.37-hab24e00_0
  font-ttf-inconsol~ conda-forge/noarch::font-ttf-inconsolata-3.000-h77eed37_0
  font-ttf-source-c~ conda-forge/noarch::font-ttf-source-code-pro-2.038-h77eed37_0
  font-ttf-ubuntu    conda-forge/noarch::font-ttf-ubuntu-0.83-hab24e00_0
  fontconfig         conda-forge/win-64::fontconfig-2.14.2-hbde0cde_0
  fonts-conda-ecosy~ conda-forge/noarch::fonts-conda-ecosystem-1-0
  fonts-conda-forge  conda-forge/noarch::fonts-conda-forge-1-0
  freetype           conda-forge/win-64::freetype-2.12.1-hdaf720e_2
  freexl             conda-forge/win-64::freexl-2.0.0-h8276f4a_0
  gdal               conda-forge/win-64::gdal-3.7.2-py312hb5f3cee_7
  geos               conda-forge/win-64::geos-3.12.0-h1537add_0
  geotiff            conda-forge/win-64::geotiff-1.7.1-hcf4a93f_14
  gettext            conda-forge/win-64::gettext-0.21.1-h5728263_0
  hdf4               conda-forge/win-64::hdf4-4.2.15-h5557f11_7
  hdf5               conda-forge/win-64::hdf5-1.14.2-nompi_h73e8ff5_100
  icu                conda-forge/win-64::icu-73.2-h63175ca_0
  importlib-metadata conda-forge/noarch::importlib-metadata-6.8.0-pyha770c72_0
  intel-openmp       conda-forge/win-64::intel-openmp-2023.2.0-h57928b3_50496
  kealib             conda-forge/win-64::kealib-1.5.2-ha10e780_1
  krb5               conda-forge/win-64::krb5-1.21.2-heb0366b_0
  lcms2              conda-forge/win-64::lcms2-2.15-h67d730c_3
  lerc               conda-forge/win-64::lerc-4.0.0-h63175ca_0
  libaec             conda-forge/win-64::libaec-1.1.2-h63175ca_1
  libarchive         conda-forge/win-64::libarchive-3.7.2-h6f8411a_0
  libblas            conda-forge/win-64::libblas-3.9.0-18_win64_mkl
  libboost-headers   conda-forge/win-64::libboost-headers-1.82.0-h57928b3_6
  libcblas           conda-forge/win-64::libcblas-3.9.0-18_win64_mkl
  libcurl            conda-forge/win-64::libcurl-8.4.0-hd5e4a3a_0
  libdeflate         conda-forge/win-64::libdeflate-1.19-hcfcfb64_0
  libexpat           conda-forge/win-64::libexpat-2.5.0-h63175ca_1
  libffi             conda-forge/win-64::libffi-3.4.2-h8ffe710_5
  libgdal            conda-forge/win-64::libgdal-3.7.2-h3217549_7
  libglib            conda-forge/win-64::libglib-2.78.0-he8f3873_0
  libhwloc           conda-forge/win-64::libhwloc-2.9.3-default_haede6df_1009
  libiconv           conda-forge/win-64::libiconv-1.17-h8ffe710_0
  libjpeg-turbo      conda-forge/win-64::libjpeg-turbo-3.0.0-hcfcfb64_1
  libkml             conda-forge/win-64::libkml-1.3.0-haf3e7a6_1018
  liblapack          conda-forge/win-64::liblapack-3.9.0-18_win64_mkl
  libnetcdf          conda-forge/win-64::libnetcdf-4.9.2-nompi_h8284064_112
  libpng             conda-forge/win-64::libpng-1.6.39-h19919ed_0
  libpq              conda-forge/win-64::libpq-16.0-h43585b0_1
  librttopo          conda-forge/win-64::librttopo-1.1.0-h92c5fdb_14
  libspatialite      conda-forge/win-64::libspatialite-5.1.0-hbf340bc_0
  libsqlite          conda-forge/win-64::libsqlite-3.43.2-hcfcfb64_0
  libssh2            conda-forge/win-64::libssh2-1.11.0-h7dfc565_0
  libtiff            conda-forge/win-64::libtiff-4.6.0-h6e2ebb7_2
  libwebp-base       conda-forge/win-64::libwebp-base-1.3.2-hcfcfb64_0
  libxml2            conda-forge/win-64::libxml2-2.11.5-hc3477c8_1
  libzip             conda-forge/win-64::libzip-1.10.1-h1d365fa_3
  libzlib            conda-forge/win-64::libzlib-1.2.13-hcfcfb64_5
  lz4-c              conda-forge/win-64::lz4-c-1.9.4-hcfcfb64_0
  lzo                conda-forge/win-64::lzo-2.10-he774522_1000
  minizip            conda-forge/win-64::minizip-4.0.1-h5bed578_5
  mkl                conda-forge/win-64::mkl-2022.1.0-h6a75c08_874
  munch              conda-forge/noarch::munch-4.0.0-pyhd8ed1ab_0
  numpy              conda-forge/win-64::numpy-1.26.0-py312h8753938_0
  openjpeg           conda-forge/win-64::openjpeg-2.5.0-h3d672ee_3
  openssl            conda-forge/win-64::openssl-3.1.3-hcfcfb64_0
  pcre2              conda-forge/win-64::pcre2-10.40-h17e33f8_0
  pip                conda-forge/noarch::pip-23.2.1-pyhd8ed1ab_0
  pixman             conda-forge/win-64::pixman-0.42.2-h63175ca_0
  poppler            conda-forge/win-64::poppler-23.10.0-hc2f3c52_0
  poppler-data       conda-forge/noarch::poppler-data-0.4.12-hd8ed1ab_0
  postgresql         conda-forge/win-64::postgresql-16.0-hc80876b_1
  proj               conda-forge/win-64::proj-9.3.0-he13c7e8_1
  pthreads-win32     conda-forge/win-64::pthreads-win32-2.9.1-hfa6e2cd_3
  python             conda-forge/win-64::python-3.12.0-h2628c8c_0_cpython
  python_abi         conda-forge/win-64::python_abi-3.12-4_cp312
  setuptools         conda-forge/noarch::setuptools-68.2.2-pyhd8ed1ab_0
  shapely            conda-forge/win-64::shapely-2.0.2-py312h92c3dd1_0
  six                conda-forge/noarch::six-1.16.0-pyh6c4a22f_0
  snappy             conda-forge/win-64::snappy-1.1.10-hfb803bf_0
  sqlite             conda-forge/win-64::sqlite-3.43.2-hcfcfb64_0
  tbb                conda-forge/win-64::tbb-2021.10.0-h91493d7_1
  tiledb             conda-forge/win-64::tiledb-2.16.3-h1ffc264_3
  tk                 conda-forge/win-64::tk-8.6.13-hcfcfb64_0
  tzdata             conda-forge/noarch::tzdata-2023c-h71feb2d_0
  ucrt               conda-forge/win-64::ucrt-10.0.22621.0-h57928b3_0
  uriparser          conda-forge/win-64::uriparser-0.9.7-h1537add_1
  vc                 conda-forge/win-64::vc-14.3-h64f974e_17
  vc14_runtime       conda-forge/win-64::vc14_runtime-14.36.32532-hdcecf7f_17
  vs2015_runtime     conda-forge/win-64::vs2015_runtime-14.36.32532-h05e6639_17
  wheel              conda-forge/noarch::wheel-0.41.2-pyhd8ed1ab_0
  xerces-c           conda-forge/win-64::xerces-c-3.2.4-h63175ca_3
  xz                 conda-forge/win-64::xz-5.2.6-h8d14728_0
  zipp               conda-forge/noarch::zipp-3.17.0-pyhd8ed1ab_0
  zlib               conda-forge/win-64::zlib-1.2.13-hcfcfb64_5
  zstd               conda-forge/win-64::zstd-1.5.5-h12be248_0


Proceed ([y]/n)?


Downloading and Extracting Packages:

Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use
#
#     $ conda activate fionatest
#
# To deactivate an active environment, use
#
#     $ conda deactivate


(testing) 
Nick@w11-virt-nh MINGW64 ~/Desktop/scratch
$ conda activate fionatest

(fionatest) 
Nick@w11-virt-nh MINGW64 ~/Desktop/scratch
$ python
Python 3.12.0 | packaged by conda-forge | (main, Oct  3 2023, 08:26:13) [MSC v.1935 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import fiona
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Nick\anaconda3\envs\fionatest\Lib\site-packages\fiona\__init__.py", line 41, in <module>
    from fiona._env import (
ImportError: DLL load failed while importing _env: The specified procedure could not be found.
>>>

Below is trying the same with my test_venv (made with the virtualenv module, fiona install with pip) and displaying the version:

Nick@w11-virt-nh MINGW64 ~/Desktop/scratch/
$ source test_venv/Scripts/activate
(test_venv) 
Nick@w11-virt-nh MINGW64 ~/Desktop/scratch/
$ python
Python 3.11.6 | packaged by conda-forge | (main, Oct  3 2023, 10:29:11) [MSC v.1935 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import fiona
>>> fiona.__version__
'1.9.5'
>>>

Answer 1

Although this did solve my issue, if someone has a more knowledgeable answer or knows why this occurred, I would still love to hear it!

After writing my question, I reread it and noticed that I said: "made with the virtualenv module, fiona install with pip"...

This lead me to attempt to remove fiona via conda, install it via pip, and then reinstall gdal with conda again. This seems to solve my issue, as I can not import both fiona and gdal, and also use fio.exe

conda uninstall fiona
pip install fiona
conda install -c conda-forge gdal

(fionatest) 
Nick@w11-virt-nh MINGW64 ~/Desktop/scratch
$ python
Python 3.12.0 | packaged by conda-forge | (main, Oct  3 2023, 08:26:13) [MSC v.1935 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import fiona
>>> from osgeo import gdal
>>> fiona.__version__
'1.9.5'
>>> gdal.__version__
'3.7.2'
>>>