azure-cli: Error "'C:\Program' is not recognized as an internal or external command" when running az role assignment create cmd

Describe the bug Running the 1st bash script in doc Authenticate with Azure Container Registry from Azure Kubernetes Service, last cmd generates error

'C:\Program' is not recognized as an internal or external command,
operable program or batch file.

Other az-cli cmds work in the same environment so far.

Environment summary Windows 10, git bash in mingw64, alias az=az.cmd

$ az --version
azure-cli                         2.0.62 *

acr                                2.2.4 *
acs                               2.3.21 *
advisor                            2.0.0
ams                                0.4.4 *
appservice                        0.2.17 *
backup                             1.2.3 *
batch                              4.0.0
batchai                            0.4.8
billing                            0.2.1
botservice                        0.1.10
cdn                                0.2.2 *
cloud                              2.1.1
cognitiveservices                  0.2.5
command-modules-nspkg               2.0.2
configure                         2.0.21 *
consumption                        0.4.2
container                         0.3.16
core                              2.0.62 *
cosmosdb                           0.2.9 *
dla                                0.2.5
dls                                0.1.8 *
dms                                0.1.3
eventgrid                          0.2.2 *
eventhubs                          0.3.4
extension                          0.2.5
feedback                           2.2.0 *
find                               0.3.2
hdinsight                          0.3.3
interactive                        0.4.3
iot                                0.3.7 *
iotcentral                         0.1.6
keyvault                          2.2.14
kusto                              0.2.2
lab                                0.1.6 *
maps                               0.3.4
monitor                           0.2.12 *
network                            2.3.6 *
nspkg                              3.0.3
policyinsights                     0.1.2
privatedns                         1.0.0
profile                            2.1.5
rdbms                              0.3.9 *
redis                              0.4.2
relay                              0.1.4
reservations                       0.4.2
resource                          2.1.13 *
role                               2.5.0 *
search                             0.1.1
security                           0.1.1
servicebus                         0.3.4
servicefabric                     0.1.16 *
signalr                            1.0.0
sql                                2.2.1 *
sqlvm                              0.1.1
storage                            2.4.0 *
telemetry                          1.0.2
vm                                2.2.18 *