install/56081: build.sh install-image fails to clean a too-small image file

[paul%whooppee.com@localhost]

>Number:         56081
>Category:       install
>Synopsis:       build.sh install-image fails to clean a too-small image file
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 28 15:45:00 +0000 2021
>Originator:     Paul Goyette
>Release:        NetBSD 9.99.80
>Organization:
+--------------------+--------------------------+-----------------------+
| Paul Goyette       | PGP Key fingerprint:     | E-mail addresses:     |
| (Retired)          | FA29 0E3B 35AF E8AE 6651 | paul%whooppee.com@localhost     |
| Software Developer | 0786 F758 55DE 53BA 7731 | pgoyette%netbsd.org@localhost   |
+--------------------+--------------------------+-----------------------+
>Environment:
	
	
System: NetBSD speedy.whooppee.com 9.99.80 NetBSD 9.99.80 (SPEEDY 2021-02-13 20:36:51 UTC) #0: Sat Feb 13 23:14:35 UTC 2021 paul%speedy.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY amd64
Architecture: x86_64
Machine: amd64
>Description:
(Filed under category install - pleasae update as appropriate!)

If you attempt a ``build.sh install-image'' and the size of the image
file is too small (specified by the INSTIMAGEMB= parameter in
src/distrib/$ARCH/installimage/Makefile), a subsequent attempt to
build the install-image target (even after updating the above build
parameter) fails due to a gpt label error.  It seems that the image
file still exists. 
seems that the too-small image file is not recreates
	
>How-To-Repeat:
1. build a release
2. temporarily reduce the INSTIMAGEMB parameter to a too-small value
3. attempt a build.sh install-image
4. restore the INSTIMAGEMB parameter's value
5. attempt another build.sh install-image
	
>Fix:
	
Check if the image size is big enough (check already exists, with an
appropriate error message), and remove the image file if too small.

>Unformatted: