Comment 1 for bug 1654946

with juju 2.8.13, it's up to 4 times:

 juju upgrade-controller --build-agent --debug
21:54:05 INFO juju.cmd supercommand.go:54 running juju [2.8.14 0 0445a6e0b3b64d8b1931b2a27dcc1d17e6c03ce6 gc go1.16.10]
21:54:05 DEBUG juju.cmd supercommand.go:55 args: []string{"juju", "upgrade-controller", "--build-agent", "--debug"}
21:54:05 INFO juju.juju api.go:67 connecting to API addresses: [10.74.147.40:17070]
21:54:05 DEBUG juju.api apiclient.go:1116 successfully dialed "wss://10.74.147.40:17070/api"
21:54:05 INFO juju.api apiclient.go:648 connection established to "wss://10.74.147.40:17070/api"
21:54:05 INFO juju.juju api.go:67 connecting to API addresses: [10.74.147.40:17070]
21:54:05 DEBUG juju.api apiclient.go:1116 successfully dialed "wss://10.74.147.40:17070/model/022b0f37-28e8-46d9-8133-0e514c7d9fd8/api"
21:54:05 INFO juju.api apiclient.go:648 connection established to "wss://10.74.147.40:17070/model/022b0f37-28e8-46d9-8133-0e514c7d9fd8/api"
21:54:05 INFO juju.juju api.go:67 connecting to API addresses: [10.74.147.40:17070]
21:54:05 DEBUG juju.api apiclient.go:1116 successfully dialed "wss://10.74.147.40:17070/model/022b0f37-28e8-46d9-8133-0e514c7d9fd8/api"
21:54:05 INFO juju.api apiclient.go:648 connection established to "wss://10.74.147.40:17070/model/022b0f37-28e8-46d9-8133-0e514c7d9fd8/api"
21:54:05 INFO juju.juju api.go:67 connecting to API addresses: [10.74.147.40:17070]
21:54:05 DEBUG juju.api apiclient.go:1116 successfully dialed "wss://10.74.147.40:17070/api"
21:54:05 INFO juju.api apiclient.go:648 connection established to "wss://10.74.147.40:17070/api"
21:54:05 DEBUG juju.cmd.juju.commands upgrademodel.go:790 searching for "" agent binaries with major: 2
21:54:08 DEBUG juju.environs.sync sync.go:311 Making agent binary tarball
21:54:08 INFO juju.environs.tools build.go:292 Building agent binary to upload (2.8.14)
21:54:08 INFO juju.environs.tools build.go:242 building jujud