merge revision(s) 4250d7c910fd67c0da07c6213901009330e3cd51,83f96642d2d74569cc38319d02d5922fac8f66b8,447feb0aa08e20cc5eeb8b3a6f881de261a2c9a2,1d80d703141f01383604022f9e8e53e10865197c,e271a3d4afc47e812b50fc9c50f6bf34d2d723a6,366e88e508de7c59d69906ad948cccd7979e932b,d825e34962540d345eb3c5a70eb264b415e915a5,4250d7c910fd67c0da07c6213901009330e3cd51,f9e43782995b1f77e7b10c79941bbbda15620e2a: [Backport #17723]

	autogen.sh: Added

	Currently it just runs "autoreconf --install"
	---
	 aclocal.m4 | 4 ++--
	 autogen.sh | 3 +++
	 2 files changed, 5 insertions(+), 2 deletions(-)
	 create mode 100755 autogen.sh

	autogen.sh: Allow AUTORECONF envvar to specify the autoreconf
	 executable

	---
	 autogen.sh | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

	Improved autogen.sh

	* update in the source directory
	* make symbolic links instead of copies
	* forward the arguments to autoreconf as-is
	---
	 autogen.sh | 8 +++++++-
	 1 file changed, 7 insertions(+), 1 deletion(-)

	autogen.sh: Make it work with sh (not bash)

	---
	 autogen.sh | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

	[DOC] Update README files to use autoreconf [ci skip]

	---
	 README.ja.md | 3 +--
	 README.md    | 3 +--
	 2 files changed, 2 insertions(+), 4 deletions(-)

	[DOC] Update README [ci skip]

	* Use `autogen.sh`.
	* The subversion repository is only for old versions, and
	  secondary now.
	* Moved long links to footnotes.
	---
	 README.ja.md | 22 +++++++++-------------
	 README.md    | 11 +++++++----
	 2 files changed, 16 insertions(+), 17 deletions(-)

	Use autogen.sh

	---
	 .github/workflows/baseruby.yml           | 2 +-
	 .github/workflows/check_dependencies.yml | 2 +-
	 .github/workflows/compilers.yml          | 2 +-
	 .github/workflows/macos.yml              | 2 +-
	 .github/workflows/mjit.yml               | 2 +-
	 .github/workflows/ubuntu.yml             | 2 +-
	 6 files changed, 6 insertions(+), 6 deletions(-)

	autogen.sh: Added

	Currently it just runs "autoreconf --install"
	---
	 aclocal.m4 | 4 ++--
	 autogen.sh | 3 +++
	 2 files changed, 5 insertions(+), 2 deletions(-)
	 create mode 100755 autogen.sh

	get rid of aclocal (#4280)

	---
	 aclocal.m4   | 47 -----------------------------------------------
	 configure.ac | 35 ++++++++++++++++++++++++++++++++++-
	 2 files changed, 34 insertions(+), 48 deletions(-)

6 files changed, 6 insertions, 6 deletions

diff --git a/.github/workflows/baseruby.yml b/.github/workflows/baseruby.yml
index bdb9011f25..16d1e4a85a 100644
--- a/.github/workflows/baseruby.yml
+++ b/.github/workflows/baseruby.yml
@@ -25,7 +25,7 @@ jobs:
           bundler: none
       - run: echo "make=make -sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
       - run: sudo apt-get install build-essential autoconf bison
-      - run: autoconf
+      - run: ./autogen.sh
       - run: ./configure --disable-install-doc
       - run: $make update-unicode
       - run: $make common-srcs
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
index c878caddeb..b5c5ea3036 100644
--- a/.github/workflows/check_dependencies.yml
+++ b/.github/workflows/check_dependencies.yml
@@ -24,7 +24,7 @@ jobs:
         run: |
           git config --global advice.detachedHead 0
       - uses: actions/checkout@v2
-      - run: autoconf
+      - run: ./autogen.sh
       - name: Run configure
         run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
       - run: make all golf
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
index 532e4589e2..b954c64bd8 100644
--- a/.github/workflows/compilers.yml
+++ b/.github/workflows/compilers.yml
@@ -167,7 +167,7 @@ jobs:
       - uses: actions/checkout@v2
         with:
           path: src
-      - run: autoconf
+      - run: ./autogen.sh
         working-directory: src
       - name: Run configure
         run: |
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index f0355258f1..c1207aaf01 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -32,7 +32,7 @@ jobs:
       - name: Set ENV
         run: |
           echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
-      - run: autoconf
+      - run: ./autogen.sh
         working-directory: src
       - name: Run configure
         run: ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
diff --git a/.github/workflows/mjit.yml b/.github/workflows/mjit.yml
index 68889ecf3d..7695a47359 100644
--- a/.github/workflows/mjit.yml
+++ b/.github/workflows/mjit.yml
@@ -35,7 +35,7 @@ jobs:
       - name: Set ENV
         run: |
           echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - run: autoconf
+      - run: ./autogen.sh
         working-directory: src
       - name: Run configure
         run: ../src/configure -C --disable-install-doc
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index fe517d2750..f222f25e7e 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -53,7 +53,7 @@ jobs:
       - name: Set ENV
         run: |
           echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - run: autoconf
+      - run: ./autogen.sh
         working-directory: src
       - name: Run configure
         run: ../src/configure -C --disable-install-doc cppflags=${{ matrix.debug }}