From 9f94d90d1ac443a04faa414102d1dc13fb31e281 Mon Sep 17 00:00:00 2001
From: Daniel <d.hornung@indiscale.com>
Date: Wed, 22 Sep 2021 17:00:49 +0200
Subject: [PATCH] ENH: Makefile works with MacOS now.

---
 .gitignore          |  9 +++++++++
 Makefile            | 23 +++++++++++++++++++++--
 doc/README_SETUP.md |  5 +++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/.gitignore b/.gitignore
index 5ed97f7..7ddf9b7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -145,3 +145,12 @@ flycheck_*.el
 
 # Python/Sphinx
 env/
+
+# Conan build files
+build_tools
+conan.lock
+conan_imports_manifest.txt
+conanbuildinfo.cmake
+conanbuildinfo.txt
+conaninfo.txt
+graph_info.json
diff --git a/Makefile b/Makefile
index a024d31..367c0de 100644
--- a/Makefile
+++ b/Makefile
@@ -23,6 +23,23 @@
 
 
 CLANG_FORMAT ?= clang-format-11
+CONAN_SETTINGS = "compiler.libcxx=libstdc++11"
+
+# OS specific handling, with code by Ken Jackson and oHo,
+# from https://stackoverflow.com/a/52062069/232888 and
+# https://stackoverflow.com/a/14777895/232888
+ifeq '$(findstring ;,$(PATH))' ';'
+	DETECTED_OS := Windows
+else
+	DETECTED_OS := $(shell uname 2>/dev/null || echo Unknown)
+	DETECTED_OS := $(patsubst CYGWIN%,Cygwin,$(DETECTED_OS))
+	DETECTED_OS := $(patsubst MSYS%,MSYS,$(DETECTED_OS))
+	DETECTED_OS := $(patsubst MINGW%,MSYS,$(DETECTED_OS))
+endif
+ifeq ($(DETECTED_OS),Darwin)  # Test if we are on MacOS
+	CONAN_SETTINGS := "cppstd=11"
+endif
+
 
 .PHONY: help
 help:
@@ -36,11 +53,13 @@ style:
 .PHONY: style
 
 conan-install:
-	conan install . -s "compiler.libcxx=libstdc++11"
+	conan install .  -s $(CONAN_SETTINGS) || \
+	  (echo "'conan install' failed, trying to build from sources..."; \
+	   conan install . -s $(CONAN_SETTINGS) --build=missing)
 .PHONY: conan-install
 
 conan-create:
-	conan create . -s "compiler.libcxx=libstdc++11"
+	conan create . -s $(CONAN_SETTINGS)
 .PHONY: conan-create
 
 conan: conan-install conan-create
diff --git a/doc/README_SETUP.md b/doc/README_SETUP.md
index a5976af..46026ee 100644
--- a/doc/README_SETUP.md
+++ b/doc/README_SETUP.md
@@ -34,6 +34,11 @@ have to add `build/lib/` (or, alternatively after installation,
 `CMAKE_INSTALL_PREFIX/lib`) to your `DYLD_LIBRARY_PATH` environmental
 variable.
 
+#### Problems and solutions ####
+
+- Make sure that your conan version supports your XCode version.  A typical symptom of version
+  mismatch is for example conan complaining about incompatible `compiler.version` settings.
+
 ### How to build on Windows
 
 We use [Visual Studio 2019](https://visualstudio.microsoft.com/de/vs/features/cplusplus/)
-- 
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