From 4c70921a84a7a1f5a827dcd4e94a35bc672d0590 Mon Sep 17 00:00:00 2001
From: Oliver Lantwin <oliver.lantwin@cern.ch>
Date: Wed, 8 Apr 2026 15:07:49 +0200
Subject: [PATCH 1/4] feat: replace ROOT builtin PCRE and VDT with external
 packages

ROOT plans to remove these builtins. Add standalone recipes for PCRE2
(10.44) and VDT (0.4.6), and configure ROOT to use them externally
instead of its bundled copies. Remove the old legacy PCRE recipe.
---
 CHANGELOG.md |  2 ++
 pcre.sh      | 18 ------------------
 pcre2.sh     | 38 ++++++++++++++++++++++++++++++++++++++
 root.sh      | 14 ++++++++------
 vdt.sh       | 33 +++++++++++++++++++++++++++++++++
 5 files changed, 81 insertions(+), 24 deletions(-)
 delete mode 100644 pcre.sh
 create mode 100644 pcre2.sh
 create mode 100644 vdt.sh

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8c70d46fa..40e3245e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ Until May 2022 (inclusive) no changelog was kept. We might try to reconstruct it
 
 ### Added
 
+* PCRE2, vdt: Add recipes to replace ROOT builtins
 * uv: Add recipe for fast Python package installation
 * Replace monolithic Python-modules with individual package recipes
 * alibuild, bitsorg: Add recipes
@@ -30,6 +31,7 @@ Until May 2022 (inclusive) no changelog was kept. We might try to reconstruct it
 
 ### Changed
 
+* ROOT: Build against external PCRE2 and VDT instead of builtins
 * EvtGen: Upgrade to R02-02-03 with HepMC3 support
 * PHOTOSPP, Tauolapp: Build with HepMC3 support
 * APFEL: Upgrade to 3.1.1 and switch to CMake build
diff --git a/pcre.sh b/pcre.sh
deleted file mode 100644
index ffa649ee4..000000000
--- a/pcre.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-package: PCRE
-version: master
-tag: master
-source: https://github.com/ktf/pcre
-prefer_system: (?!slc5)
-prefer_system_check: |
-  printf "#include \"pcre.h\"\n" | gcc -xc++ - -c -o /dev/null
----
-#!/bin/sh
-echo "Building our own pcre. If you want to avoid this, please install pcre development package."
-
-$SOURCEDIR/configure --enable-unicode-properties \
-                     --enable-pcregrep-libz \
-                     --enable-pcregrep-libbz2 \
-                     --prefix=$INSTALLROOT
-
-make ${JOBS+-j $JOBS}
-make install
diff --git a/pcre2.sh b/pcre2.sh
new file mode 100644
index 000000000..2227b8de3
--- /dev/null
+++ b/pcre2.sh
@@ -0,0 +1,38 @@
+package: PCRE2
+version: "%(tag_basename)s"
+tag: pcre2-10.44
+source: https://github.com/PCRE2Project/pcre2
+build_requires:
+  - "GCC-Toolchain:(?!osx)"
+  - CMake
+prefer_system: (?!slc5)
+prefer_system_check: |
+  printf "#include \"pcre2.h\"\n" | c++ -xc++ -DPCRE2_CODE_UNIT_WIDTH=8 - -c -M 2>&1
+---
+#!/bin/bash -e
+cmake "$SOURCEDIR" -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
+                   -DCMAKE_BUILD_TYPE="$CMAKE_BUILD_TYPE" \
+                   -DPCRE2_SUPPORT_UNICODE=ON             \
+                   -DPCRE2_BUILD_PCRE2_8=ON               \
+                   -DPCRE2_BUILD_PCRE2_16=OFF             \
+                   -DPCRE2_BUILD_PCRE2_32=OFF
+
+cmake --build . ${JOBS:+-j$JOBS} --target install
+
+# Modulefile
+MODULEDIR="$INSTALLROOT/etc/modulefiles"
+mkdir -p "$MODULEDIR"
+cat > "$MODULEDIR/$PKGNAME" <<EoF
+#%Module1.0
+proc ModulesHelp { } {
+  global version
+  puts stderr "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
+}
+set version $PKGVERSION-@@PKGREVISION@$PKGHASH@@
+module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
+# Dependencies
+module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
+# Our environment
+set PCRE2_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
+prepend-path LD_LIBRARY_PATH \$PCRE2_ROOT/lib
+EoF
diff --git a/root.sh b/root.sh
index 1a6836d12..66327551e 100644
--- a/root.sh
+++ b/root.sh
@@ -14,6 +14,8 @@ requires:
   - XRootD
   - pythia
   - TBB
+  - PCRE2
+  - vdt
 build_requires:
   - CMake
   - libxml2
@@ -46,7 +48,7 @@ prefer_system_check: |
       echo "ROOT version $VERSION insufficient ($REQUESTED_VERSION requested)"
       exit 1
   fi
-  FEATURES="builtin_pcre mathmore xml ssl opengl http gdml pythia8 roofit soversion vdt xrootd"
+  FEATURES="mathmore xml ssl opengl http gdml pythia8 roofit soversion vdt xrootd"
   for FEATURE in $FEATURES; do
       root-config --has-$FEATURE | grep -q yes || { echo "$FEATURE missing"; exit 1; }
   done
@@ -70,7 +72,7 @@ cmake $SOURCEDIR \
 ${XROOTD_ROOT:+-DXROOTD_ROOT_DIR=$XROOTD_ROOT}            \
 -DCMAKE_CXX_STANDARD=$CMAKE_CXX_STANDARD                  \
 -Dbuiltin_freetype=OFF                                    \
--Dbuiltin_pcre=ON                                         \
+-Dbuiltin_pcre=OFF                                        \
 -DCMAKE_CXX_COMPILER=$COMPILER_CXX                        \
 -DCMAKE_C_COMPILER=$COMPILER_CC                           \
 -DCMAKE_LINKER=$COMPILER_LD                               \
@@ -81,15 +83,15 @@ ${PYTHIA_ROOT:+-Dpythia8=ON}                \
 -Dmathmore=ON \
 -Dsoversion=ON                                            \
 -Dshadowpw=OFF                                            \
--Dbuiltin_vdt=ON                                          \
+-Dbuiltin_vdt=OFF                                         \
 -Dbuiltin_davix=OFF                                                              \
 -Ddavix=OFF                                                                      \
 ${PYTHON_ROOT:+-DPYTHON_EXECUTABLE=$PYTHONHOME/bin/python3} \
 ${PYTHON_ROOT:+-DPython3_ROOT_DIR=$PYTHON_ROOT} \
--DCMAKE_PREFIX_PATH="$FREETYPE_ROOT;$GSL_ROOT;$PYTHON_ROOT"
-FEATURES="builtin_pcre xml ssl opengl http gdml mathmore ${PYTHIA_ROOT:+pythia8}
+-DCMAKE_PREFIX_PATH="$FREETYPE_ROOT;$GSL_ROOT;$PYTHON_ROOT;$PCRE2_ROOT;$VDT_ROOT"
+FEATURES="xml ssl opengl http gdml mathmore ${PYTHIA_ROOT:+pythia8}
     roofit soversion vdt ${XROOTD_ROOT:+xrootd}"
-NO_FEATURES="${FREETYPE_ROOT:+builtin_freetype}"
+NO_FEATURES="builtin_pcre builtin_vdt ${FREETYPE_ROOT:+builtin_freetype}"
 
 # Check if all required features are enabled
 bin/root-config --features
diff --git a/vdt.sh b/vdt.sh
new file mode 100644
index 000000000..2180537df
--- /dev/null
+++ b/vdt.sh
@@ -0,0 +1,33 @@
+package: vdt
+version: "%(tag_basename)s"
+tag: v0.4.6
+source: https://github.com/dpiparo/vdt
+build_requires:
+  - CMake
+  - "GCC-Toolchain:(?!osx)"
+prefer_system_check: |
+  printf "#include \"vdt/vdtMath.h\"\n" | c++ -xc++ - -c -M 2>&1
+---
+#!/bin/bash -e
+cmake "$SOURCEDIR" -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
+                   -DCMAKE_BUILD_TYPE="$CMAKE_BUILD_TYPE"
+
+cmake --build . ${JOBS:+-j$JOBS} --target install
+
+# Modulefile
+MODULEDIR="$INSTALLROOT/etc/modulefiles"
+mkdir -p "$MODULEDIR"
+cat > "$MODULEDIR/$PKGNAME" <<EoF
+#%Module1.0
+proc ModulesHelp { } {
+  global version
+  puts stderr "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
+}
+set version $PKGVERSION-@@PKGREVISION@$PKGHASH@@
+module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
+# Dependencies
+module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
+# Our environment
+set VDT_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
+prepend-path LD_LIBRARY_PATH \$VDT_ROOT/lib
+EoF

From 94af3d0233442c34684309c3df90f6b9f01f0630 Mon Sep 17 00:00:00 2001
From: Oliver Lantwin <oliver.lantwin@cern.ch>
Date: Wed, 8 Apr 2026 19:26:04 +0200
Subject: [PATCH 2/4] fix: set CMP0144 policy so packages find VDT_ROOT

Several packages using older CMake minimum versions don't honour
<PKG>_ROOT variables by default. Enable CMP0144 (and the minimum
policy version for vdt itself) so they pick up VDT_ROOT correctly.
---
 geant3.sh        | 1 +
 genfit.sh        | 1 +
 rootegpythia6.sh | 1 +
 vdt.sh           | 3 ++-
 vgm.sh           | 1 +
 5 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/geant3.sh b/geant3.sh
index fb003d3d6..be6b33712 100644
--- a/geant3.sh
+++ b/geant3.sh
@@ -33,6 +33,7 @@ cmake $SOURCEDIR -DCMAKE_INSTALL_PREFIX=$INSTALLROOT      \
                  -DCMAKE_SKIP_RPATH=TRUE \
 		 -DCMAKE_POLICY_DEFAULT_CMP0074=NEW \
                  -DCMAKE_C_FLAGS="$CFLAGS -std=gnu17" \
+		 -DCMAKE_POLICY_DEFAULT_CMP0144=NEW \
                  ${SPECIALFFLAGS:+-DCMAKE_Fortran_FLAGS="-fallow-argument-mismatch -fallow-invalid-boz -fno-tree-loop-distribute-patterns"}
 make ${JOBS:+-j $JOBS} install
 
diff --git a/genfit.sh b/genfit.sh
index 8cf3061f6..c4a31c8e1 100644
--- a/genfit.sh
+++ b/genfit.sh
@@ -39,6 +39,7 @@ cmake $SOURCEDIR
       -DCMAKE_INSTALL_LIBDIR=lib                                                            \
       -DCMAKE_INSTALL_PREFIX=$INSTALLROOT \
       -DCMAKE_POLICY_DEFAULT_CMP0074=NEW \
+      -DCMAKE_POLICY_DEFAULT_CMP0144=NEW \
       -DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
       -DROOT_DIR="${ROOT_ROOT}" \
       -DBUILD_TESTING=${BUILD_TESTING}
diff --git a/rootegpythia6.sh b/rootegpythia6.sh
index 83ba9e4e7..84587daa6 100644
--- a/rootegpythia6.sh
+++ b/rootegpythia6.sh
@@ -35,6 +35,7 @@ cmake "$SOURCEDIR" \
       -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
       -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} \
       -DROOTEGPythia6_Pythia6_BUILTIN=ON \
+      -DCMAKE_POLICY_DEFAULT_CMP0144=NEW \
       -DCMAKE_INSTALL_LIBDIR=lib
 
 cmake --build . ${JOBS:+-j$JOBS}
diff --git a/vdt.sh b/vdt.sh
index 2180537df..af46dd407 100644
--- a/vdt.sh
+++ b/vdt.sh
@@ -10,7 +10,8 @@ prefer_system_check: |
 ---
 #!/bin/bash -e
 cmake "$SOURCEDIR" -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
-                   -DCMAKE_BUILD_TYPE="$CMAKE_BUILD_TYPE"
+	-DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
+	-DCMAKE_BUILD_TYPE="$CMAKE_BUILD_TYPE"
 
 cmake --build . ${JOBS:+-j$JOBS} --target install
 
diff --git a/vgm.sh b/vgm.sh
index 9323440c6..229541ed5 100644
--- a/vgm.sh
+++ b/vgm.sh
@@ -35,6 +35,7 @@ cmake "$SOURCEDIR" \
   -DWITH_TEST=OFF                     \
   ${XERCESC_ROOT:+-DXercesC_ROOT=$XERCESC_ROOT} \
   -DCMAKE_POLICY_DEFAULT_CMP0074=NEW \
+  -DCMAKE_POLICY_DEFAULT_CMP0144=NEW \
   -DBUILD_SHARED_LIBS=OFF
 #  ${XERCESC_ROOT:+-DXercesC_INCLUDE_DIR=$XERCESC_ROOT/include -DXercesC_LIBRARY=$XERCESC_ROOT/lib} \
 

From 735dce2c6749dcbe65d9f3cf809ff0afebbde22c Mon Sep 17 00:00:00 2001
From: Oliver Lantwin <oliver.lantwin@cern.ch>
Date: Mon, 27 Apr 2026 11:52:53 +0200
Subject: [PATCH 3/4] fix: export PCRE2_ROOT and VDT_ROOT as environment
 variables

Use setenv instead of set in modulefiles so these variables are visible
to downstream builds like root.sh's CMAKE_PREFIX_PATH.
---
 pcre2.sh | 4 ++--
 vdt.sh   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pcre2.sh b/pcre2.sh
index 2227b8de3..dde93eaae 100644
--- a/pcre2.sh
+++ b/pcre2.sh
@@ -33,6 +33,6 @@ module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@
 # Dependencies
 module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
 # Our environment
-set PCRE2_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
-prepend-path LD_LIBRARY_PATH \$PCRE2_ROOT/lib
+setenv PCRE2_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
+prepend-path LD_LIBRARY_PATH \$::env(PCRE2_ROOT)/lib
 EoF
diff --git a/vdt.sh b/vdt.sh
index af46dd407..a2c82152b 100644
--- a/vdt.sh
+++ b/vdt.sh
@@ -29,6 +29,6 @@ module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@
 # Dependencies
 module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
 # Our environment
-set VDT_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
-prepend-path LD_LIBRARY_PATH \$VDT_ROOT/lib
+setenv VDT_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
+prepend-path LD_LIBRARY_PATH \$::env(VDT_ROOT)/lib
 EoF

From cdd9eeac1e54b4e4c5ec2ba7dc9736d3f6e1b329 Mon Sep 17 00:00:00 2001
From: Oliver Lantwin <oliver.lantwin@cern.ch>
Date: Tue, 28 Apr 2026 09:47:23 +0200
Subject: [PATCH 4/4] refactor: use alibuild-generate-module

Replace handwritten modulefile boilerplate in PCRE2 and vdt recipes
with the standard generator, matching other recipes.
---
 pcre2.sh | 19 +++----------------
 vdt.sh   | 19 +++----------------
 2 files changed, 6 insertions(+), 32 deletions(-)

diff --git a/pcre2.sh b/pcre2.sh
index dde93eaae..61d6a432e 100644
--- a/pcre2.sh
+++ b/pcre2.sh
@@ -5,6 +5,7 @@ source: https://github.com/PCRE2Project/pcre2
 build_requires:
   - "GCC-Toolchain:(?!osx)"
   - CMake
+  - alibuild-recipe-tools
 prefer_system: (?!slc5)
 prefer_system_check: |
   printf "#include \"pcre2.h\"\n" | c++ -xc++ -DPCRE2_CODE_UNIT_WIDTH=8 - -c -M 2>&1
@@ -20,19 +21,5 @@ cmake "$SOURCEDIR" -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
 cmake --build . ${JOBS:+-j$JOBS} --target install
 
 # Modulefile
-MODULEDIR="$INSTALLROOT/etc/modulefiles"
-mkdir -p "$MODULEDIR"
-cat > "$MODULEDIR/$PKGNAME" <<EoF
-#%Module1.0
-proc ModulesHelp { } {
-  global version
-  puts stderr "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
-}
-set version $PKGVERSION-@@PKGREVISION@$PKGHASH@@
-module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
-# Dependencies
-module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
-# Our environment
-setenv PCRE2_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
-prepend-path LD_LIBRARY_PATH \$::env(PCRE2_ROOT)/lib
-EoF
+mkdir -p "$INSTALLROOT/etc/modulefiles"
+alibuild-generate-module --lib > "$INSTALLROOT/etc/modulefiles/$PKGNAME"
diff --git a/vdt.sh b/vdt.sh
index a2c82152b..657cf7e03 100644
--- a/vdt.sh
+++ b/vdt.sh
@@ -5,6 +5,7 @@ source: https://github.com/dpiparo/vdt
 build_requires:
   - CMake
   - "GCC-Toolchain:(?!osx)"
+  - alibuild-recipe-tools
 prefer_system_check: |
   printf "#include \"vdt/vdtMath.h\"\n" | c++ -xc++ - -c -M 2>&1
 ---
@@ -16,19 +17,5 @@ cmake "$SOURCEDIR" -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
 cmake --build . ${JOBS:+-j$JOBS} --target install
 
 # Modulefile
-MODULEDIR="$INSTALLROOT/etc/modulefiles"
-mkdir -p "$MODULEDIR"
-cat > "$MODULEDIR/$PKGNAME" <<EoF
-#%Module1.0
-proc ModulesHelp { } {
-  global version
-  puts stderr "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
-}
-set version $PKGVERSION-@@PKGREVISION@$PKGHASH@@
-module-whatis "ALICE Modulefile for $PKGNAME $PKGVERSION-@@PKGREVISION@$PKGHASH@@"
-# Dependencies
-module load BASE/1.0 ${GCC_TOOLCHAIN_REVISION:+GCC-Toolchain/$GCC_TOOLCHAIN_VERSION-$GCC_TOOLCHAIN_REVISION}
-# Our environment
-setenv VDT_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
-prepend-path LD_LIBRARY_PATH \$::env(VDT_ROOT)/lib
-EoF
+mkdir -p "$INSTALLROOT/etc/modulefiles"
+alibuild-generate-module --lib > "$INSTALLROOT/etc/modulefiles/$PKGNAME"