debian packaging tool broken in Ubuntu Mate 18.04

[Roland]

Trying to build a package on ubuntu mate 18.04 64-bit with all updates applied. Builds on Ubuntu 18.04 just fine.

How broke is this error?

pkg-deb: error: maintainer script 'preinst' has bad permissions 644 (must be >=0555 and <=0775)

eveloper@roland-HP-EliteDesk-800-G1-SFF:~/my_branch/build-scripts$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic
d

[Roland (seasoned-geek)]

Just tried this in a shiny new 14.04 64-bit VM and got the same error.

~/my_branch/build-scripts
BUILDSH: Build and rename .deb file
dpkg-deb: error: maintainer script `preinst' has bad permissions 644 (must be >=0555 and <=0775)

[Roland (seasoned-geek)]

How is this invalid? I'm seeing it all over the place. The bug has been cropping up since 1999!

In case you use that new new new new math, let me tell you that 644 is BOTH >= 555 AND <= 775

[Roland (seasoned-geek)]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=48914

https://<email address hidden>/msg13505.html

[Martin Wimpress  (flexiondotorg)]

You are asking for support, you have not identified a bug. You are citing your own scripts with no reproducible test case.

If you can identify a bug in a package shipped by Ubuntu MATE then raise an issue using `ubuntu-bug packagename`.

[Roland (seasoned-geek)]

Your recent updates broke debian packaging.

The script in question builds debian packages dozens of times per day and has been running for years.

Most everybody else is just changing their package to use 775 since that is one of the few values which works.

WHAT IS BROKEN IS THE TEST

This keeps resurfacing in this fix-it-break-it-fix-it-break-it AGILE development world.

Take ANY EXISTING BIULD SCRIPT. chmod 0644 the preinst, postinst, etc files and when you hit this step

# Build and rename .deb file.
echo "BUILDSH: Build and rename .deb file"
fakeroot dpkg-deb -Zgzip --build debian

it will fail in a manner which is completely obvious.

dpkg-deb: error: maintainer script `preinst' has bad permissions 644 (must be >=0555 and <=0775)

644 is well within that range, and, for many years was the standard.