Kill ambient LIBNEO_* env footgun; use LIBNEO_REF cache var only

.github/workflows/main.yml

@@ -12,7 +12,7 @@ on:
         required: false
         default: ''
       full:
-        description: run the full suite (fast + slow + regression); nightly only
+        description: run the full suite (fast + slow + regression); set by the libneo full-ci gate
         required: false
         default: 'false'
 
@@ -23,9 +23,6 @@ permissions:
   checks: write
   actions: read
 
-env:
-  LIBNEO_BRANCH: ${{ inputs.libneo_ref || github.head_ref || github.ref_name }}
-
 jobs:
   test:
     name: Build and Test
@@ -83,7 +80,12 @@ jobs:
       - name: Build SIMPLE (deterministic FP for reproducibility)
         run: |
           make clean
-          make build-deterministic
+          REF="${{ inputs.libneo_ref }}"
+          if [ -n "$REF" ]; then
+            make build-deterministic LIBNEO_REF="$REF"
+          else
+            make build-deterministic
+          fi
 
       # libneo-gate dispatch (no full) runs only the sub-minute smoke set;
       # push, PR and full=true run the complete suite below.
@@ -165,9 +167,13 @@ jobs:
       - name: Run CGAL Wall Unit Tests (CGAL enabled, minimal)
         run: |
           make clean
+          REF="${{ inputs.libneo_ref }}"
+          LIBNEO_ARG=""
+          if [ -n "$REF" ]; then LIBNEO_ARG="LIBNEO_REF=$REF"; fi
           make test-fast CONFIG=Fast \
             FLAGS='-DSIMPLE_ENABLE_CGAL=ON -DENABLE_PYTHON_INTERFACE=OFF -DSIMPLE_ENABLE_PYTHON_TOOLS=OFF' \
-            TEST='test_chartmap_metadata|test_stl_wall_intersection'
+            TEST='test_chartmap_metadata|test_stl_wall_intersection' \
+            $LIBNEO_ARG
 
   build-docs:
     name: Build Documentation

CMakeLists.txt

@@ -224,6 +224,18 @@ else()
     message(STATUS "Fortplot disabled for NVHPC compiler (compatibility issues)")
 endif()
 
+# fortnum provides the multidimensional root finder (multiroot_hybrids) that
+# replaced the bundled MINPACK hybrd1 in orbit_symplectic_quasi.
+if(NOT TARGET fortnum)
+    include(FetchContent)
+    FetchContent_Declare(
+        fortnum
+        GIT_REPOSITORY https://github.com/lazy-fortran/fortnum.git
+        GIT_TAG 92de6e949a772cfffc73bb5295fe5e2b056b9c18
+    )
+    FetchContent_MakeAvailable(fortnum)
+endif()
+
 if (SIMPLE_TESTING)
     message(STATUS "Unit Tests enabled!")
 endif()

Makefile

@@ -1,6 +1,17 @@
 CONFIG ?= Release
 FLAGS ?=
 BUILD_DIR := build
+
+# Prevent ambient shell env from silently changing which libneo is fetched.
+# Pass the ref explicitly via: make ... LIBNEO_REF=<branch|tag|sha>
+# $(origin) distinguishes a command-line assignment from an env import.
+unexport LIBNEO_REF LIBNEO_PATH LIBNEO_BRANCH
+ifeq ($(origin LIBNEO_REF),command line)
+  FLAGS += -DLIBNEO_REF=$(LIBNEO_REF)
+endif
+ifeq ($(origin LIBNEO_PATH),command line)
+  FLAGS += -DLIBNEO_SOURCE_DIR=$(LIBNEO_PATH)
+endif
 BUILD_NINJA := $(BUILD_DIR)/build.ninja
 PYTHON_FOR_TESTS := $(if $(wildcard .venv/bin/python),$(CURDIR)/.venv/bin/python,python)
 SIMPLE_GVEC_QA_CACHE_ROOT ?= $(HOME)/data/SIMPLE/gvec_qa_roundtrip

README.md

@@ -19,6 +19,21 @@ The code is free to use and modify under the MIT License and links to Runge-Kutt
 Run `make` to produce a `build` directory including the main executable
 `simple.x`, main library `libsimple.so` and Python module `pysimple`.
 
+To build against a specific libneo branch, tag, or commit SHA, pass it
+explicitly; the ambient shell environment is intentionally ignored:
+
+```bash
+make LIBNEO_REF=my-branch          # via make
+cmake -DLIBNEO_REF=my-branch ...   # via cmake directly
+```
+
+To use a local libneo checkout instead of fetching from GitHub:
+
+```bash
+make LIBNEO_PATH=/path/to/libneo
+cmake -DLIBNEO_SOURCE_DIR=/path/to/libneo ...
+```
+
 Required build tools:
 * CMake (>= 3.22)
 * Ninja

cmake/Util.cmake

@@ -72,13 +72,10 @@ function(find_or_fetch DEPENDENCY)
     if("${_dep_lower}" STREQUAL "libneo")
         set(_repo_url "https://github.com/itpplasma/libneo.git")
         set(_branch "")
-        set(_branch_source "")
-        if(DEFINED LIBNEO_BRANCH AND NOT "${LIBNEO_BRANCH}" STREQUAL "")
-            string(STRIP "${LIBNEO_BRANCH}" _branch)
-            set(_branch_source "cache")
-        elseif(DEFINED ENV{LIBNEO_BRANCH} AND NOT "$ENV{LIBNEO_BRANCH}" STREQUAL "")
-            string(STRIP "$ENV{LIBNEO_BRANCH}" _branch)
-            set(_branch_source "env")
+
+        # Override via -DLIBNEO_REF=<branch|tag|sha>; never read from $ENV.
+        if(DEFINED LIBNEO_REF AND NOT "${LIBNEO_REF}" STREQUAL "")
+            string(STRIP "${LIBNEO_REF}" _branch)
         endif()
 
         if(NOT _branch STREQUAL "")
@@ -93,8 +90,7 @@ function(find_or_fetch DEPENDENCY)
                 set(_branch_valid TRUE)
             endif()
             if(NOT _branch_valid)
-                message(WARNING "LIBNEO branch '${_branch}' (source: ${_branch_source}) not found; falling back to main")
-                set(_branch "")
+                message(WARNING "LIBNEO_REF='${_branch}' not found as a branch; treating as tag or SHA")
             endif()
         endif()
 

src/CMakeLists.txt

@@ -1,8 +1,6 @@
     set(SOURCES
         ${CMAKE_BINARY_DIR}/version.f90
         lapack_interfaces.f90
-        contrib/minpack_interfaces.f90
-        contrib/minpack.f90
         sorting_mod.f90
         wall/chartmap_metadata.f90
         wall/stl_wall_intersection.F90
@@ -99,11 +97,6 @@ target_link_libraries(simple PUBLIC pyplot)
 # Apply SIMPLE-specific compile options
 target_compile_options(simple PRIVATE ${SIMPLE_COMPILE_OPTIONS})
 
-if(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
-    set_source_files_properties(contrib/minpack.f90 PROPERTIES
-        COMPILE_FLAGS "-Wno-compare-reals -Wno-implicit-interface -Wno-maybe-uninitialized")
-endif()
-
 # Apply trampoline error flags only to SIMPLE library (not subprojects like fortplot)
 if(CMAKE_Fortran_COMPILER_ID STREQUAL "GNU")
     target_compile_options(simple PRIVATE
@@ -120,6 +113,10 @@ target_link_libraries(simple PUBLIC
     LIBNEO::neo
 )
 
+target_link_libraries(simple PUBLIC
+    fortnum
+)
+
 # For NVHPC: add built deps includes first to avoid gfortran-compiled modules in /usr/include
 if(CMAKE_Fortran_COMPILER_ID STREQUAL "NVHPC")
     target_include_directories(simple BEFORE PUBLIC