debian/rules.d/build.mk: egrep -> grep -E.

debian/changelog

@@ -4,6 +4,7 @@ glibc (2.35-0experimental3) UNRELEASED; urgency=medium
   * debian/control.in/libc: add a breaks against valgrind (<< 1:3.19.0-1~).
     See #1017791.
   * debian/debhelper.in/libc-bin.install: install /usr/bin/ld.so.
+  * debian/rules.d/build.mk: egrep -> grep -E.
  -- Aurelien Jarno <aurel32@debian.org>  Sun, 28 Aug 2022 13:45:56 +0200

debian/rules.d/build.mk

@@ -174,7 +174,7 @@ $(stamp)check_%: $(stamp)build_%
 	    echo "|     Encountered regressions that don't match expected failures.     |" ; \
 	    echo "+---------------------------------------------------------------------+" ; \
 	    grep -E '^FAIL:' $(DEB_BUILDDIR)/tests.sum | sort ; \
-	    if ! echo $(DEB_VERSION) | egrep -q '^Version:.*\+deb[0-9]+u[0-9]+' ; then \
+	    if ! echo $(DEB_VERSION) | grep -q -E '^Version:.*\+deb[0-9]+u[0-9]+' ; then \
 	        touch $@_failed ; \
 	    fi ; \
 	  else \