From a7ad872553651bfa4f9c31f15ec8c733150b3063 Mon Sep 17 00:00:00 2001
From: Patrick Avery <patrick.avery@kitware.com>
Date: Tue, 28 Nov 2023 12:10:30 -0600
Subject: [PATCH] Install pybind11 if it is missing

We currently support 3 different build setups:

1. In a conda environment (uses pybind11 conda package in build step)
2. In a regular pip environment (uses pybind11 in build isolation as specified in pyproject.toml)
3. In a conda development environment (no build isolation)

This PR fixes number 3.

pybind11 is not a runtime dependency for the conda environment, so if a user
installs the HEXRD prerelease, it won't come with pybind11. Then, if a user
tries to make a dev environment, pybind11 won't be available.

The changes here make it so that in situation number 3, the pybind11 source
code is downloaded automatically and installed, so that the headers can
be found.

Signed-off-by: Patrick Avery <patrick.avery@kitware.com>
---
 scripts/install/install_build_dependencies.py | 14 +++++++++-----
 setup.py                                      | 16 ++++++++++++++--
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/scripts/install/install_build_dependencies.py b/scripts/install/install_build_dependencies.py
index ca1688faa..2e35e2de4 100755
--- a/scripts/install/install_build_dependencies.py
+++ b/scripts/install/install_build_dependencies.py
@@ -76,13 +76,17 @@ def download_pybind11(path):
     md5sum = '90c4946e87c64d8d8fc0ae4edf35d780'
     out_dir_name = 'pybind11-2.11.0'
 
-    download_and_extract_tgz(url, md5sum, path)
+    with tempfile.TemporaryDirectory() as temp_dir:
+        download_and_extract_tgz(url, md5sum, temp_dir)
 
-    target_path = Path(path) / 'pybind11'
-    if target_path.exists():
-        shutil.rmtree(target_path)
+        target_path = Path(path) / 'pybind11'
+        if target_path.exists():
+            shutil.rmtree(target_path)
+
+        os.makedirs(path, exist_ok=True)
+        shutil.move(str(Path(temp_dir) / out_dir_name / 'include/pybind11'),
+                    str(Path(path) / 'pybind11/pybind11'))
 
-    shutil.move(str(Path(path) / out_dir_name), str(Path(path) / 'pybind11'))
 
     return str(target_path)
 
diff --git a/setup.py b/setup.py
index d0372da90..03bac969b 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,6 @@
 import sys
 
 import numpy
-import pybind11
 np_include_dir = numpy.get_include()
 
 install_reqs = [
@@ -93,6 +92,19 @@ def get_include_path(library_name):
     return full_path
 
 
+def get_pybind11_include_path():
+    # If we can import pybind11, use that include path
+    try:
+        import pybind11
+    except ImportError:
+        pass
+    else:
+        return pybind11.get_include()
+
+    # Otherwise, we will download the source and include that
+    return get_include_path('pybind11')
+
+
 def get_cpp_extensions():
     cpp_transform_pkgdir = Path('hexrd') / 'transforms/cpp_sublibrary'
     src_files = [str(cpp_transform_pkgdir / 'src/inverse_distortion.cpp')]
@@ -106,7 +118,7 @@ def get_cpp_extensions():
     include_dirs = [
         get_include_path('eigen3'),
         get_include_path('xsimd'),
-        pybind11.get_include(),
+        get_pybind11_include_path(),
         numpy.get_include(),
     ]