package libcurl3 (not installed) failed to install/upgrade: conflicting packages - not installing libcurl3:amd64

[janjula]

On upgrade 15.04 to18. 04

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: libcurl3 (not installed)
ProcVersionSignature: Ubuntu 4.4.0-122.146-generic 4.4.117
Uname: Linux 4.4.0-122-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Sun May 13 00:14:17 2018
ErrorMessage: conflicting packages - not installing libcurl3:amd64
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: curl3
Title: package libcurl3 (not installed) failed to install/upgrade: conflicting packages - not installing libcurl3:amd64
UpgradeStatus: Upgraded to bionic on 2018-05-12 (0 days ago)

[Dimitri John Ledkov (xnox)]

15.04 to 18.04 is not a supported upgrade path.

One must upgrade to 16.04 first, reboot, then upgrade to 18.04. Or is that a typo?

[Dimitri John Ledkov (xnox)]

curl3 was removed in cosmic; but this may still affect bionic; marking cosmic as fix-released and keeping bionic task open.