[MacPorts] #71126: MacOSX10.13.sdk fails to install on 10.15 Catalina

[MacPorts]

#71126: MacOSX10.13.sdk fails to install on 10.15 Catalina
------------------------------+------------------------
  Reporter:  rmottola         |      Owner:  ryandesign
      Type:  defect           |     Status:  assigned
  Priority:  Normal           |  Milestone:
 Component:  ports            |    Version:
Resolution:                   |   Keywords:  catalina
      Port:  MacOSX10.13.sdk  |
------------------------------+------------------------

Comment (by kencu):

 when working with this port, you will likely run into a "resource is busy
 error". Get past that like this:

 {{{
 $ diskutil list
 /dev/disk0 (internal, physical):
    #:                       TYPE NAME                    SIZE
 IDENTIFIER
    0:      GUID_partition_scheme                        *68.7 GB    disk0
    1:                        EFI EFI                     209.7 MB
 disk0s1
    2:                  Apple_HFS Macintosh HD            67.7 GB
 disk0s2
    3:                 Apple_Boot Recovery HD             650.0 MB
 disk0s3

 /dev/disk1 (disk image):
    #:                       TYPE NAME                    SIZE
 IDENTIFIER
    0:      GUID_partition_scheme                        +460.9 MB   disk1
    1:                  Apple_HFS Command Line Develop... 460.9 MB
 disk1s1

 VMdarwi12Sierra:MacOSX.sdk$ sudo hdiutil unmount /dev/disk1
 "/dev/disk1" was already unmounted.
 VMdarwi12Sierra:MacOSX.sdk$ sudo hdiutil detach /dev/disk1
 "disk1" unmounted.
 "disk1" ejected.
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/71126#comment:9>
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