update-initramfs doesn't consider free space in /var/tmp

[Avamander]

Low disk space in /var/tmp mount causes post-installation script to fail. It should probably detect it.

ProblemType: Package
DistroRelease: Ubuntu 19.10
Package: initramfs-tools 0.133ubuntu10
ProcVersionSignature: Ubuntu 5.3.0-1023.25-raspi2 5.3.18
Uname: Linux 5.3.0-1023-raspi2 aarch64
ApportVersion: 2.20.11-0ubuntu8.8
Architecture: arm64
Date: Tue May 19 00:23:34 2020
ErrorMessage: installed initramfs-tools package post-installation script subprocess returned error exit status 1
PackageArchitecture: all
Python3Details: /usr/bin/python3.7, Python 3.7.5, python3-minimal, 3.7.5-1
PythonDetails: /usr/bin/python2.7, Python 2.7.17, python-minimal, 2.7.17-1
RelatedPackageVersions:
 dpkg 1.19.7ubuntu2
 apt 1.9.4ubuntu0.1
SourcePackage: initramfs-tools
Title: package initramfs-tools 0.133ubuntu10 failed to install/upgrade: installed initramfs-tools package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to eoan on 2020-05-19 (0 days ago)