Fix CI issues (#3906)

Co-authored-by: barcode <barcode@example.com>

.cirrus.yml

@@ -1,13 +1,8 @@
-kind: pipeline
-name: test-on-arm64
+arm_container:
+  image: gcc:latest
 
-platform:
-  arch: arm64
-
-steps:
-- name: build
-  image: gcc
-  commands:
+check_task:
+  check_script:
   - wget https://github.com/Kitware/CMake/releases/download/v3.20.2/cmake-3.20.2.tar.gz
   - tar xfz cmake-3.20.2.tar.gz
   - cd cmake-3.20.2

.github/workflows/ubuntu.yml

@@ -146,6 +146,9 @@ jobs:
       - uses: actions/checkout@v3
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@latest
+      - name: Set env FORCE_STDCPPFS_FLAG for clang 7 / 8 / 9 / 10
+        run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
+        if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build

README.md

@@ -1140,7 +1140,7 @@ Please note:
 
 - Unsupported versions of GCC and Clang are rejected by `#error` directives. This can be switched off by defining `JSON_SKIP_UNSUPPORTED_COMPILER_CHECK`. Note that you can expect no support in this case.
 
-The following compilers are currently used in continuous integration at [AppVeyor](https://ci.appveyor.com/project/nlohmann/json), [Drone CI](https://cloud.drone.io/nlohmann/json), and [GitHub Actions](https://github.com/nlohmann/json/actions):
+The following compilers are currently used in continuous integration at [AppVeyor](https://ci.appveyor.com/project/nlohmann/json), [Cirrus CI](https://cirrus-ci.com/github/nlohmann/json), and [GitHub Actions](https://github.com/nlohmann/json/actions):
 
 | Compiler                                                                                               | Operating System   | CI Provider    |
 |--------------------------------------------------------------------------------------------------------|--------------------|----------------|
@@ -1190,7 +1190,7 @@ The following compilers are currently used in continuous integration at [AppVeyo
 | GCC 8.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
 | GCC 9.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
 | GCC 10.4.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 11.1.0                                                                                             | Ubuntu (aarch64)   | Drone CI       |
+| GCC 11.1.0                                                                                             | Ubuntu (aarch64)   | Cirrus CI      |
 | GCC 11.3.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
 | GCC 12.2.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
 | GCC 13.0.0 20220605 (experimental)                                                                     | Ubuntu 20.04.3 LTS | GitHub Actions |

cmake/ci.cmake

@@ -901,12 +901,7 @@ add_custom_target(ci_cmake_flags
 foreach(COMPILER g++-4.8 g++-4.9 g++-5 g++-6 g++-7 g++-8 g++-9 g++-10 g++-11 clang++-3.5 clang++-3.6 clang++-3.7 clang++-3.8 clang++-3.9 clang++-4.0 clang++-5.0 clang++-6.0 clang++-7 clang++-8 clang++-9 clang++-10 clang++-11 clang++-12 clang++-13 clang++-14)
     find_program(COMPILER_TOOL NAMES ${COMPILER})
     if (COMPILER_TOOL)
-        if ("${COMPILER}" STREQUAL "clang++-9")
-            # fix for https://github.com/nlohmann/json/pull/3101#issuecomment-998788786 / https://stackoverflow.com/a/64051725/266378
-            set(ADDITIONAL_FLAGS "-DCMAKE_CXX_FLAGS=--gcc-toolchain=/root/gcc/9")
-        else()
-            unset(ADDITIONAL_FLAGS)
-        endif()
+        unset(ADDITIONAL_FLAGS)
 
         add_custom_target(ci_test_compiler_${COMPILER}
             COMMAND CXX=${COMPILER} ${CMAKE_COMMAND}

tests/CMakeLists.txt

@@ -6,6 +6,15 @@ option(JSON_FastTests   "Skip expensive/slow tests." OFF)
 set(JSON_32bitTest     AUTO CACHE STRING "Enable the 32bit unit test (ON/OFF/AUTO/ONLY).")
 set(JSON_TestStandards "" CACHE STRING "The list of standards to test explicitly.")
 
+# using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
+set(JSON_FORCED_GLOBAL_COMPILE_OPTIONS $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
+if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}")
+    add_compile_options($ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
+endif()
+if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_LINK_OPTIONS}")
+    add_link_options($ENV{JSON_FORCED_GLOBAL_LINK_OPTIONS})
+endif()
+
 include(test)
 
 #############################################################################

tests/src/unit-regression2.cpp

@@ -37,7 +37,9 @@ using ordered_json = nlohmann::ordered_json;
 #endif
 
 #ifdef JSON_HAS_CPP_20
-    #include <span>
+    #if __has_include(<span>)
+        #include <span>
+    #endif
 #endif
 
 // NLOHMANN_JSON_SERIALIZE_ENUM uses a static std::pair
@@ -664,6 +666,7 @@ TEST_CASE("regression tests 2")
     }
 
 #ifdef JSON_HAS_CPP_20
+#if __has_include(<span>)
     SECTION("issue #2546 - parsing containers of std::byte")
     {
         const char DATA[] = R"("Hello, world!")"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
@@ -671,6 +674,7 @@ TEST_CASE("regression tests 2")
         const json j = json::parse(s);
         CHECK(j.dump() == "\"Hello, world!\"");
     }
+#endif
 #endif
 
     SECTION("issue #2574 - Deserialization to std::array, std::pair, and std::tuple with non-default constructable types fails")