env/openbsd-amd64: create OpenBSD 6.8 builder images

Update the openbsd-{386,amd64} builder script to create OpenBSD 6.8 images.

Updates golang/go#35712

Change-Id: I7b306f7c99c02ae0c2eab57bdf2c463b11aa507f
Reviewed-on: https://go-review.googlesource.com/c/build/+/268297
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/env/openbsd-amd64/README b/env/openbsd-amd64/README
index f253d62..27cf883 100644
--- a/env/openbsd-amd64/README
+++ b/env/openbsd-amd64/README
@@ -7,13 +7,13 @@
 After it completes, it creates a file openbsd-amd64-gce.tar.gz
 
 Then:
-    gsutil cp -a public-read openbsd-amd64-gce.tar.gz gs://go-builder-data/openbsd-amd64-64-snap1.tar.gz
+    gsutil cp -a public-read openbsd-amd64-gce.tar.gz gs://go-builder-data/openbsd-amd64-68.tar.gz
 Or just use the web UI at:
     https://console.developers.google.com/project/symbolic-datum-552/storage/browser/go-builder-data/
 
 Then:
-   gcloud compute --project symbolic-datum-552 images delete openbsd-amd64-64-snap1
-   gcloud compute --project symbolic-datum-552 images create openbsd-amd64-64-snap1 --source-uri gs://go-builder-data/openbsd-amd64-64-snap1.tar.gz
+   gcloud compute --project symbolic-datum-552 images delete openbsd-amd64-68
+   gcloud compute --project symbolic-datum-552 images create openbsd-amd64-68 --source-uri gs://go-builder-data/openbsd-amd64-68.tar.gz
 
 The VM needs to be run with the GCE metadata attribute "buildlet-binary-url" set to a URL
 of the OpenBSD buildlet (cross-compiled, typically).
diff --git a/env/openbsd-amd64/make.bash b/env/openbsd-amd64/make.bash
index a87e639..9b0f7b9 100755
--- a/env/openbsd-amd64/make.bash
+++ b/env/openbsd-amd64/make.bash
@@ -8,12 +8,12 @@
 set -e
 set -u
 
-readonly VERSION="6.4"
+readonly VERSION="6.8"
 readonly RELNO="${VERSION/./}"
 readonly SNAPSHOT=false
 
 readonly ARCH="${ARCH:-amd64}"
-readonly MIRROR="${MIRROR:-ftp.usa.openbsd.org}"
+readonly MIRROR="${MIRROR:-cdn.openbsd.org}"
 
 if [[ "${ARCH}" != "amd64" && "${ARCH}" != "i386" ]]; then
   echo "ARCH must be amd64 or i386"
@@ -46,9 +46,6 @@
 
 trap cleanup EXIT INT
 
-# XXX: Download and save bash, curl, and their dependencies too?
-# Currently we download them from the network during the install process.
-
 # Create custom siteXX.tgz set.
 PKG_ADD_OPTIONS=""
 if [[ "$SNAPSHOT" = true ]]; then
@@ -117,6 +114,7 @@
 Use (W)hole disk or (E)dit the MBR = whole
 Use (A)uto layout, (E)dit auto layout, or create (C)ustom layout = auto
 URL to autopartitioning template for disklabel = file://disklabel.template
+Location of sets = cd0
 Set name(s) = +* -x* -game* -man* done
 Directory does not contain SHA256.sig. Continue without verification = yes
 EOF
@@ -165,18 +163,7 @@
 send "exit\n"
 
 expect timeout { exit 1 } "CONGRATULATIONS!"
-
-# There is some form of race condition with OpenBSD 6.2 MP
-# and qemu, which can result in init(1) failing to run /bin/sh
-# the first time around...
-expect {
-  timeout { exit 1 }
-  "Enter pathname of shell or RETURN for sh:" {
-    send "\nexit\n"
-    expect timeout { exit 1 } eof
-  }
-  eof
-}
+expect timeout { exit 1 } eof
 EOF
 
 # Create Compute Engine disk image.