Trying the last option like this:
===== src/upgrade.c 1.63 vs edited =====
--- 1.63/src/upgrade.c 2016-09-17 11:13:50 -04:00
+++ edited/src/upgrade.c 2017-09-19 14:21:19 -04:00
@@ -446,6 +446,9 @@
if (time(0) - mtime(buf) > DAY) {
/* latest-bkver file is old, start update in background */
av = addLine(av, "bk");
+
+ /* avoid atexit() tests that can hang in regressions */
+ av = addLine(av, "-?BK_REGRESSION=");
av = addLine(av, "upgrade");
av = addLine(av, "--update-latest");
av = addLine(av, 0);
undocumented option: "bk '-?VAR=val&VAR2=val2' cmd" can set things in the environment of a bk command. Yeah, "env VAR=val bk cmd" would do the same thing.)