GH-49901: [R] Bump minimum supported R version to 4.2 now that 4.6 is out

.github/workflows/r.yml

@@ -205,7 +205,7 @@ jobs:
       fail-fast: false
       matrix:
         config:
-        - { rtools: 40, arch: 'ucrt64' }
+        - { rtools: 42, arch: 'ucrt64' }
     steps:
       - run: git config --global core.autocrlf false
       - name: Checkout Arrow
@@ -228,10 +228,10 @@ jobs:
             r-${{ matrix.config.rtools }}-ccache-mingw-${{ matrix.config.arch }}-
       - uses: r-lib/actions/setup-r@v2
         with:
-          # Note: RTools must be 40 here because RTools40 + ucrt is how we build the Arrow C++
-          # static library. The R is not used here but R 4.1 was the last R to use
-          # Rtools40.
-          r-version: "4.1"
+          # Note: RTools must be 42 here because RTools42 + ucrt is how we build the Arrow C++
+          # static library. The R is not used here but R 4.2 was the last R to use
+          # Rtools42.
+          r-version: "4.2"
           rtools-version: ${{ matrix.config.rtools }}
           Ncpus: 2
       - name: Build Arrow C++
@@ -284,14 +284,14 @@ jobs:
       - name: Download Timezone Database
         shell: bash
         run: |
-          # RTools 40 uses GCC 8.x which does not support C++20 chrono timezones,
-          # so Arrow uses the vendored date library which requires tzdata
+          # MinGW (non-MSVC) builds use the vendored date library for timezone
+          # handling, which requires a local copy of the IANA tzdata database.
           ci/scripts/download_tz_database.sh
       - run: mkdir r/windows
       - name: Download artifacts
         uses: actions/download-artifact@v8
         with:
-          name: libarrow-rtools40-ucrt64.zip
+          name: libarrow-rtools42-ucrt64.zip
           path: r/windows
       - name: Unzip and rezip libarrows
         shell: bash

ci/scripts/r_windows_build.sh

@@ -23,6 +23,22 @@ set -ex
 # Make sure it is absolute and exported
 export ARROW_HOME="$(cd "${ARROW_HOME}" && pwd)"
 
+# Debug: understand the RTools environment on this runner
+echo "=== RTools debug info ==="
+echo "Shell: $SHELL / BASH: $BASH"
+echo "MSYSTEM: $MSYSTEM"
+echo "RTOOLS_VERSION: $RTOOLS_VERSION"
+echo "which bash: $(which bash)"
+echo "which pacman: $(which pacman)"
+echo "which strip: $(which strip 2>/dev/null || echo 'not found')"
+echo "which makepkg-mingw: $(which makepkg-mingw 2>/dev/null || echo 'not found')"
+ls -la /usr/ssl/certs/ 2>/dev/null || echo "/usr/ssl/certs/ does not exist"
+ls -la /etc/pki/ca-trust/ 2>/dev/null || echo "/etc/pki/ca-trust/ does not exist"
+ls /c/rtools42/ 2>/dev/null || echo "/c/rtools42/ does not exist"
+ls /c/rtools45/ 2>/dev/null || echo "/c/rtools45/ does not exist"
+echo "cygpath /: $(cygpath -w /)"
+echo "=== end debug ==="
+
 pacman --noconfirm -Syy
 
 RWINLIB_LIB_DIR="lib"

dev/tasks/macros.jinja

@@ -277,8 +277,6 @@ env:
   {# use filter to cast to string and convert to lowercase to match yaml boolean #}
   {% set is_fork = (not is_upstream_b)|lower %}
 
-{% set r_release = {"ver": "4.2", "rt" : "42"} %}
-{% set r_oldrel = {"ver": "4.1", "rt" : "40"} %}
 
 {%- macro github_set_env(env) -%}
   {% if env is defined %}

dev/tasks/r/github.linux.arrow.version.back.compat.yml

@@ -90,10 +90,8 @@ jobs:
         - { old_arrow_version: '10.0.1', r: '4.2' }
         - { old_arrow_version: '9.0.0', r: '4.2' }
         - { old_arrow_version: '8.0.0', r: '4.2' }
-        - { old_arrow_version: '7.0.0', r: '4.1' }
-        - { old_arrow_version: '6.0.1', r: '4.1' }
-        - { old_arrow_version: '5.0.0', r: '4.1' }
-        - { old_arrow_version: '4.0.0', r: '4.1' }
+        - { old_arrow_version: '7.0.0', r: '4.2' }
+        - { old_arrow_version: '6.0.1', r: '4.2' }
     env:
       ARROW_R_DEV: "TRUE"
       OLD_ARROW_VERSION: {{ '${{ matrix.config.old_arrow_version }}' }}

dev/tasks/r/github.linux.versions.yml

@@ -30,7 +30,6 @@ jobs:
         r_version:
           # We test devel, release, and oldrel in regular CI.
           # This is for older versions
-          - "4.1"
           - "4.2"
           - "4.3"
           - "4.4"

r/DESCRIPTION

@@ -22,7 +22,7 @@ Description: 'Apache' 'Arrow' <https://arrow.apache.org/> is a cross-language
     language-independent columnar memory format for flat and hierarchical data,
     organized for efficient analytic operations on modern hardware. This
     package provides an interface to the 'Arrow C++' library.
-Depends: R (>= 4.1)
+Depends: R (>= 4.2)
 License: Apache License (>= 2.0)
 URL: https://github.com/apache/arrow/, https://arrow.apache.org/docs/r/
 BugReports: https://github.com/apache/arrow/issues