--refresh should be implied

[kparal]

I have just run this:

$ sudo dnf system-upgrade download --releasever=24 --allowerasing

and was shown this:

Downloading Packages:
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://download.eng.brq.redhat.com/pub/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://download.eng.brq.redhat.com/pub/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://download.eng.brq.redhat.com/pub/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.vutbr.cz/fedora/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://mirror.slu.cz/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Downloading successful, but checksum doesn't match. Calculated: 8feebc27aa326861bdd5197496f28ed3f90d6ea5ce710243b4f954b97d614198(sha256)  Expected: dc7702ad7525a7e35cd45987effb86a4a128fd36dc43f7f5f1e7665085ee4ed5(sha256) 
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Downloading successful, but checksum doesn't match. Calculated: 8feebc27aa326861bdd5197496f28ed3f90d6ea5ce710243b4f954b97d614198(sha256)  Expected: 809b3b95321f1e95da4eadd1d57ec7143dc0d1a148b2c7e1e09f09be475b95ee(sha256) 
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Downloading successful, but checksum doesn't match. Calculated: 8feebc27aa326861bdd5197496f28ed3f90d6ea5ce710243b4f954b97d614198(sha256)  Expected: 274859efd0681df4c9aaa6f6066aff743f95981340e9b7988c61f33b2ddef84a(sha256) 
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://ftp.halifax.rwth-aachen.de/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-libs-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://ftp.halifax.rwth-aachen.de/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-libs-python3-2.5-3.fc24.x86_64.rpm: Curl error (78): Remote file not found for ftp://ftp.halifax.rwth-aachen.de/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-libs-python3-2.5-3.fc24.x86_64.rpm [RETR response: 550]
[MIRROR] audit-2.5-3.fc24.x86_64.rpm: Status code: 404 for http://ftp.halifax.rwth-aachen.de/fedora/linux/development/24/Everything/x86_64/os/Packages/a/audit-2.5-3.fc24.x86_64.rpm

(and on and on and on, I hit Ctrl+C after a minute or so)

When I executed the same command again but with --refresh, everything went fine and packages were correctly downloaded.

General users don't know this, so let's avoid it. When running system-upgrade, always imply --refresh. Because when doing a distro upgrade, we always want to make sure we have the latest metadata and latest packages.

dnf-plugin-system-upgrade-0.7.1-1.fc23.noarch