packaging error: cmake-3.16.3-1

[Bob Tracy <rct@frus.com>]

"apt-get upgrade" is failing on "cmake_3.16.3-1_alpha.deb" with the
following errors for the past day:

Get:1 http://ftp.ports.debian.org/debian-ports unstable/main alpha cmake alpha 3.16.3-1 [3,531 kB]
Err:1 http://ftp.ports.debian.org/debian-ports unstable/main alpha cmake alpha 3.16.3-1
  File has unexpected size (3529328 != 3530656). Mirror sync in progress? [IP: 2001:4f8:1:c::15 80]
  Hashes of expected file:
   - SHA512:f2edd4855fb556ab719479c89b72f05054624b8e905240d613f4631e473e90f681d70c7c8f46d6063bd21b54e1f8d65bf3b6bb94532f16458be03c798a1f610d
   - SHA256:f0b6df816e19a005727a49ed362f5ddbf66c8f088ad9def36f443f687d985af7
   - SHA1:6fbd019ddd13bfd770d1ce0468c860f6ac857c33 [weak]
   - MD5Sum:b531b2ce6a59006d99ee0eff9eccd8af [weak]
   - Filesize:3530656 [weak]
E: Failed to fetch http://ftp.ports.debian.org/debian-ports/pool-alpha/main/c/cmake/cmake_3.16.3-1_alpha.deb  File has unexpected size (3529328 != 3530656). Mirror sync in progress? [IP: 2001:4f8:1:c::15 80]
   Hashes of expected file:
    - SHA512:f2edd4855fb556ab719479c89b72f05054624b8e905240d613f4631e473e90f681d70c7c8f46d6063bd21b54e1f8d65bf3b6bb94532f16458be03c798a1f610d
    - SHA256:f0b6df816e19a005727a49ed362f5ddbf66c8f088ad9def36f443f687d985af7
    - SHA1:6fbd019ddd13bfd770d1ce0468c860f6ac857c33 [weak]
    - MD5Sum:b531b2ce6a59006d99ee0eff9eccd8af [weak]
    - Filesize:3530656 [weak]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?