diff --git a/Makefile b/Makefile
index 7daa881..d4762db 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 
 # Somewhat superseeded by fedpkg
 
-BRANCH := $(shell fedpkg switch-branch | sed -n -e 's/ f/ /' -e 's/master/rawhide/' -e 's/^\* //p')
+BRANCH := $(shell fedpkg switch-branch | sed -n -e 's/ f/ /' -e 's/main/rawhide/' -e 's/^\* //p')
 SPEC_FILE = $(shell fedpkg gimmespec)
 
 # VERREL is very slow
diff --git a/frysk-0.4-50-autoconf-2-70-fixes.patch b/frysk-0.4-50-autoconf-2-70-fixes.patch
new file mode 100644
index 0000000..e00d989
--- /dev/null
+++ b/frysk-0.4-50-autoconf-2-70-fixes.patch
@@ -0,0 +1,119 @@
+diff --git a/frysk-common/frysk-common.ac b/frysk-common/frysk-common.ac
+index c9a2be863..7e0bbb0d0 100644
+--- a/frysk-common/frysk-common.ac
++++ b/frysk-common/frysk-common.ac
+@@ -89,13 +89,13 @@ export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/$lib/frysk/pkgconfig
+ 
+ # Check for XMLLINT
+ AC_CHECK_PROGS([XMLLINT], [xmllint], [no])
+-test $XMLLINT = no && AC_ERROR([no xmllint program found])
++test $XMLLINT = no && AC_MSG_ERROR([no xmllint program found])
+ AC_CHECK_PROGS([XMLCATALOG], [xmlcatalog], [no])
+-test $XMLCATALOG = no && AC_ERROR([no xmlcatalog program found])
++test $XMLCATALOG = no && AC_MSG_ERROR([no xmlcatalog program found])
+ 
+ # Check for uudecode
+ AC_CHECK_PROGS([UUDECODE], [uudecode], [no])
+-test $UUDECODE = no && AC_ERROR([no uudecode program found, please install sharutils package])
++test $UUDECODE = no && AC_MSG_ERROR([no uudecode program found, please install sharutils package])
+ 
+ FRYSK_USE_LIBUNWIND
+ 
+diff --git a/frysk-core/configure.ac b/frysk-core/configure.ac
+index 69fc220b3..d0fe07c3a 100644
+--- a/frysk-core/configure.ac
++++ b/frysk-core/configure.ac
+@@ -37,7 +37,7 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk, [FRYSK_VERSION])
+diff --git a/frysk-gtk/configure.ac b/frysk-gtk/configure.ac
+index aaa123f82..55c592ebf 100644
+--- a/frysk-gtk/configure.ac
++++ b/frysk-gtk/configure.ac
+@@ -36,7 +36,7 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk, [FRYSK_VERSION])
+diff --git a/frysk-gui/configure.ac b/frysk-gui/configure.ac
+index 9a274c68b..ec5950d2a 100644
+--- a/frysk-gui/configure.ac
++++ b/frysk-gui/configure.ac
+@@ -36,7 +36,7 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk, [FRYSK_VERSION])
+diff --git a/frysk-imports/configure.ac b/frysk-imports/configure.ac
+index b9a6c32c3..e65f4c433 100644
+--- a/frysk-imports/configure.ac
++++ b/frysk-imports/configure.ac
+@@ -37,7 +37,7 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk, [FRYSK_VERSION])
+diff --git a/frysk-imports/libunwind/configure.ac b/frysk-imports/libunwind/configure.ac
+index 7fa2e4bcf..37c9072a0 100644
+--- a/frysk-imports/libunwind/configure.ac
++++ b/frysk-imports/libunwind/configure.ac
+@@ -57,7 +57,6 @@ esac
+ CHECK_ATOMIC_OPS
+ 
+ dnl Checks for header files.
+-AC_HEADER_STDC
+ AC_CHECK_HEADERS(asm/ptrace_offsets.h endian.h sys/endian.h execinfo.h \
+ 		ia64intrin.h sys/uc_access.h unistd.h signal.h sys/types.h \
+ 		sys/procfs.h sys/ptrace.h byteswap.h elf.h sys/elf.h link.h sys/link.h)
+diff --git a/frysk-sys/configure.ac b/frysk-sys/configure.ac
+index 6a1e0cad8..4f838439d 100644
+--- a/frysk-sys/configure.ac
++++ b/frysk-sys/configure.ac
+@@ -36,7 +36,7 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk, [FRYSK_VERSION])
+diff --git a/frysk-top/configure.ac b/frysk-top/configure.ac
+index f57136a56..ee68665d3 100644
+--- a/frysk-top/configure.ac
++++ b/frysk-top/configure.ac
+@@ -36,14 +36,14 @@
+ # version and license this file solely under the GPL without
+ # exception.
+ 
+-AC_PREREQ(2.59)
++AC_PREREQ([2.70])
+ 
+ sinclude(common/version.ac)
+ AC_INIT(frysk,defn([FRYSK_VERSION]))
+ m4_include([common/frysk-common.ac])
+ 
+ AC_ARG_ENABLE(gnome,
+-AC_HELP_STRING(
++AS_HELP_STRING(
+ 	[--enable-gnome],
+ 	[enable gnome user interface (default no)]),
+ [enable_gnome=$enableval],
diff --git a/frysk.spec b/frysk.spec
index 7ae2e6d..2d27734 100644
--- a/frysk.spec
+++ b/frysk.spec
@@ -1,7 +1,7 @@
 Summary:	Execution analysis and debugging tool-suite
 Name:		frysk
 Version:	0.4
-Release:	77%{?dist}
+Release:	78%{?dist}
 
 # Fedora 17+ is still waiting for vte et.al. bindings.
 %define enable_gnome %{fedora}0 < 170
@@ -68,6 +68,7 @@ Patch46:	frysk-0.4-javac.patch
 Patch47:	frysk-0.4-jnixx-union-as-reserved-word.patch
 Patch48:	frysk-0.4-jnixx-dont-emit-nested-classes.patch
 Patch49:	frysk-0.4-49-elf-newehdr-null.patch
+Patch50:	frysk-0.4-50-autoconf-2-70-fixes.patch
 
 Patch100:	frysk-0.4-aclocaljavac.patch
 Patch101:	frysk-0.4-cxx-scope.patch
@@ -272,6 +273,7 @@ mv frysk-imports/libunwind/configure.{in,ac}
 %patch47 -p1 -z .jnixx-union-as-reserved-word
 %patch48 -p1 -z .jnixx-dont-emit-nested-classes
 %patch49 -p1 -z .49-elf-newehdr-null
+%patch50 -p1 -z .50-autoconf-2-70-fixes
 
 echo "%{version}-%{release}" > frysk-common/version.in
 
@@ -454,6 +456,9 @@ rm $RPM_BUILD_ROOT%{_libdir}/%{name}/funit-*-nodebug
 %endif
 
 %changelog
+* Mon Apr 12 2021 Andrew Cagney <cagney@fedoraproject.org> - 0.4-78
+- autoconf 2.70
+
 * Tue Jan 26 2021 Fedora Release Engineering <releng@fedoraproject.org> - 0.4-77
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild