[Conan] append to LDFLAGS in profile instead of overriding them

Author: tttapa

.github/workflows/python-build/action.yml

@@ -99,9 +99,9 @@ runs:
         tools.cmake.cmaketoolchain:generator=Ninja Multi-Config
         tools.build:skip_test=true
         [buildenv]
-        CFLAGS=-fdiagnostics-color
-        CXXFLAGS=-fdiagnostics-color
-        LDFLAGS=-static-libgcc -static-libstdc++ -flto=auto
+        CFLAGS+= -fdiagnostics-color
+        CXXFLAGS+= -fdiagnostics-color
+        LDFLAGS+= -static-libgcc -static-libstdc++ -flto=auto
         EOF
 
     # Custom recipes needed for some of the dependencies.

.github/workflows/wheel.yml

@@ -70,9 +70,9 @@ jobs:
           tools.cmake.cmaketoolchain:generator=Ninja Multi-Config
           tools.build:skip_test=true
           [buildenv]
-          CFLAGS=-fdiagnostics-color
-          CXXFLAGS=-fdiagnostics-color
-          LDFLAGS=-static-libgcc -static-libstdc++ -flto=auto
+          CFLAGS+= -fdiagnostics-color
+          CXXFLAGS+= -fdiagnostics-color
+          LDFLAGS+= -static-libgcc -static-libstdc++ -flto=auto
           EOF
       - name: Install Conan recipes
         run: |

scripts/dev/install-locally.sh

@@ -43,9 +43,9 @@ tools.build:skip_test=true
 tools.build.cross_building:can_run=true
 tools.cmake.cmaketoolchain:generator=Ninja Multi-Config
 [buildenv]
-CFLAGS=-march=native -fdiagnostics-color
-CXXFLAGS=-march=native -fdiagnostics-color
-LDFLAGS=-static-libstdc++ -flto=auto
+CFLAGS+= -march=native -fdiagnostics-color
+CXXFLAGS+= -march=native -fdiagnostics-color
+LDFLAGS+= -static-libstdc++ -flto=auto
 EOF
 python_profile="$PWD/profile-python.local.conan"
 cat <<- EOF > "$python_profile"
@@ -57,9 +57,9 @@ tools.cmake.cmaketoolchain:generator=Ninja Multi-Config
 tools.build.cross_building:can_run=true
 tools.build:skip_test=true
 [buildenv]
-CFLAGS=-march=native -fdiagnostics-color
-CXXFLAGS=-march=native -fdiagnostics-color
-LDFLAGS=-static-libgcc -static-libstdc++ -flto=auto
+CFLAGS+= -march=native -fdiagnostics-color
+CXXFLAGS+= -march=native -fdiagnostics-color
+LDFLAGS+= -static-libgcc -static-libstdc++ -flto=auto
 EOF
 
 # Build and install alpaqa dependencies