--- /cygdrive/c/comp/perl-5.33.2/sv.c   2020-10-04 18:15:27.028350200 +1100
+++ sv.c        2020-10-04 18:13:55.508841200 +1100
@@ -13109,13 +13109,17 @@
                 /* check, in manner not involving wrapping, that it will
                  * fit in ebuf  */
                 && float_need < sizeof(ebuf)
-                && sizeof(ebuf) - float_need > precis
+                && sizeof(ebuf) - float_need > precis + 7
                 && !(width || left || plus || alt)
                 && !fill
                 && intsize != 'q'
             ) {
                 WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric,
-                    SNPRINTF_G(fv, ebuf, sizeof(ebuf), precis)
+#if defined(USE_LONG_DOUBLE)
+                    PERL_UNUSED_RESULT(sprintf(ebuf, "%.*Lg", (int)precis, (NV) fv))
+#else
+                    PERL_UNUSED_RESULT(sprintf(ebuf, "%.*g",  (int)precis, (NV) fv))
+#endif
                 );
                 elen = strlen(ebuf);
                 eptr = ebuf;

##</code><code>##

--- sprintf2.t_orig     2020-10-04 18:24:56 +1100
+++ sprintf2.t  2020-10-04 18:24:37 +1100
@@ -1178,4 +1178,25 @@
     is($off2, 1, "offset after 0");
 }

+# %g formatting was broken on Ubuntu, Debian and perhaps other systems
+# for a long time. Here we verify that no such breakage still exists.
+
+if($Config{nvsize} == 8) {
+    cmp_ok(sprintf("%.54g", 0.3), 'eq', '0.299999999999999988897769753748434595
763683319091796875',
+           "sprintf( \"%.54g\", 0.3 ) renders correctly");
+}
+elsif($Config{nvtype} eq 'long double' && ($Config{longdblkind} == 3 || $Config
{longdblkind} == 4)) {
+    cmp_ok(sprintf("%.64g", 0.3), 'eq', '0.300000000000000000010842021724855044
3400745280086994171142578125',
+           "sprintf( \"%.64g\", 0.3 ) renders correctly");
+}
+elsif($Config{nvtype} eq 'long double' && $Config{longdblkind} >= 5 && $Config{
longdblkind} <= 8) {
+    # oops ... TODO (for double-double)
+else {
+    cmp_ok(sprintf("%.115g", 0.3), 'eq',
+           '0.29999999999999999999999999999999999037035027806382073472011028707
5363407309491758923059023800306022167205810546875',
+           "sprintf( \"%.115g\", 0.3 ) renders correctly");
+}
+
+
 done_testing();