[MacPorts] #71975: py312-pymc @5.20.0: checksum mismatch

[MacPorts]

#71975: py312-pymc @5.20.0: checksum mismatch
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  Reporter:  ryandesign  |      Owner:  reneeotten
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.10.5
Resolution:              |   Keywords:
      Port:  py312-pymc  |
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Comment (by ryandesign):

 A checksum issue wouldn't be random, though it could seem that way.
 MacPorts picks what server to download from based on which one is closest.
 If you switch the source of a distfile to one that has a different file of
 the same name and you update the checksums in the port, as you did, but
 the old file is mirrored on our servers, then if MacPorts fetches from our
 mirror there will be a checksum mismatch and if MacPorts fetches from the
 new upstream server there will not.

 The purpose of the stealth update recipe is to prevent checksum
 mismatches. Any given path in distfiles space (whether that be on a mirror
 or on a user's machine) should only be used once.
 [changeset:66b557551421ea05dcdfed9224766b0f115cd723/macports-ports On
 January 8] you used the distfiles path py-pymc/pymc-5.20.0.tar.gz for a
 file with size 6874233 bytes. Both users and servers may have fetched that
 file. Then [changeset:839620e67d6c0141cdf1deb6307c8055b227c45c/macports-
 ports on January 29] you reused that same path for a different file, one
 with size 487357 bytes. Anyone (servers, users) who still has the old file
 gets a checksum mismatch, therefore the stealth update procedure (which
 changes the path by changing `dist_subdir`) should have been employed, or
 the problem could have been avoided by waiting to make the change together
 with a version update.

 When the buildbot mirroring process encounters a checksum mismatch it
 deletes the file from the primary mirror. (I disagree with the decision to
 do that, but it's what it currently does.) That deletion then synchronizes
 to the other mirrors over the course of several hours. Nothing causes the
 mismatching distfile to be deleted from user systems so following the
 stealth update recipe is still important to prevent some users from
 encountering the problem.

-- 
Ticket URL: <https://trac.macports.org/ticket/71975#comment:2>
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