From fb643c4c4dad33aa674eb09407c0caa6e41c2d42 Mon Sep 17 00:00:00 2001
From: Michael Steinbaugh <mike@steinbaugh.com>
Date: Fri, 25 Aug 2023 21:04:05 -0400
Subject: [PATCH] Add support for `ldpaths` detection on macOS via
 `DYLD_FALLBACK_LIBRARY_PATH` (#417)

---
 radian/app.py | 43 ++++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/radian/app.py b/radian/app.py
index 0a87a9b..1da7937 100644
--- a/radian/app.py
+++ b/radian/app.py
@@ -75,35 +75,48 @@ def main(cleanup=None):
     if not r_home:
         raise RuntimeError("Cannot find R binary. Expose it via the `PATH` variable.")
 
-    if sys.platform.startswith("linux"):
-        # respect R_ARCH variable?
+    if not sys.platform.startswith("win"):
         libPath = os.path.join(r_home, "lib")
         ldpaths = os.path.join(r_home, "etc", "ldpaths")
-        if "R_LD_LIBRARY_PATH" not in os.environ or libPath not in os.environ["R_LD_LIBRARY_PATH"]:
+        if (
+            "R_LD_LIBRARY_PATH" not in os.environ
+            or libPath not in os.environ["R_LD_LIBRARY_PATH"]
+        ):
             if os.path.exists(ldpaths):
-                R_LD_LIBRARY_PATH = subprocess.check_output(
-                    ". \"{}\"; echo $R_LD_LIBRARY_PATH".format(ldpaths),
-                    shell=True
-                ).decode("utf-8").strip()
+                R_LD_LIBRARY_PATH = (
+                    subprocess.check_output(
+                        '. "{}"; echo $R_LD_LIBRARY_PATH'.format(ldpaths),
+                        shell=True,
+                    )
+                    .decode("utf-8")
+                    .strip()
+                )
             elif "R_LD_LIBRARY_PATH" in os.environ:
                 R_LD_LIBRARY_PATH = os.environ["R_LD_LIBRARY_PATH"]
             else:
                 R_LD_LIBRARY_PATH = libPath
-
             if libPath not in R_LD_LIBRARY_PATH:
                 R_LD_LIBRARY_PATH = "{}:{}".format(libPath, R_LD_LIBRARY_PATH)
-
-            os.environ['R_LD_LIBRARY_PATH'] = R_LD_LIBRARY_PATH
-
-            if "LD_LIBRARY_PATH" in os.environ:
-                LD_LIBRARY_PATH = "{}:{}".format(R_LD_LIBRARY_PATH, os.environ["LD_LIBRARY_PATH"])
+            os.environ["R_LD_LIBRARY_PATH"] = R_LD_LIBRARY_PATH
+            # respect R_ARCH variable?
+            if sys.platform == "darwin":
+                ld_library_var = "DYLD_FALLBACK_LIBRARY_PATH"
+            else:
+                ld_library_var = "LD_LIBRARY_PATH"
+            if ld_library_var in os.environ:
+                LD_LIBRARY_PATH = "{}:{}".format(
+                    R_LD_LIBRARY_PATH, os.environ[ld_library_var]
+                )
             else:
                 LD_LIBRARY_PATH = R_LD_LIBRARY_PATH
-            os.environ['LD_LIBRARY_PATH'] = LD_LIBRARY_PATH
+            os.environ[ld_library_var] = LD_LIBRARY_PATH
             if sys.argv[0].endswith("radian"):
                 os.execv(sys.argv[0], sys.argv)
             else:
-                os.execv(sys.executable, [sys.executable, "-m", "radian"] + sys.argv[1:])
+                os.execv(
+                    sys.executable,
+                    [sys.executable, "-m", "radian"] + sys.argv[1:],
+                )
 
     RadianApplication(r_home, ver=__version__).run(options, cleanup=cleanup)