Hello, Validated software needs to ensure consistency and reproducibility of its environment, potentially in years' time, when the audit comes. For this reason, we identify all SHA of the packages we download from CRAN to ensure that the package has not changed after the fact, something that may signal us that the package has been corrupted, or malicious code has been added after the fact, and also guarantees the auditors that the packages are indeed the correct ones as they were at the time of release.
Currently I am dealing with a package that I downloaded once in the past, MASS_7.3-54. This package used to have SHA256 b800ccd5b5c2709b1559cf5eab126e4935c4f8826cf7891253432bb6a056e821 MASS_7.3-54.tar.gz The current package has instead SHA: eb644c0e94b447c46387aa22436ef5a43192960ee9cfd0df2940f4a4116179ae MASS_7.3-54.tar.gz This triggers all sort of alarms. It is established poor practice to replace a package after the fact exact for these reasons. Once a package is released, it should remain immutable. Subsequent builds can be introduced with a different build number. The change appears to be due to the fact that CRAN rebuilds packages occasionally, for reasons to me unknown. Diffing the old and the new MASS_7.3.54.tar.gz reveals the change to be due to this: $ diff -Naur MASS_1/ MASS_2/ diff -Naur MASS_1/DESCRIPTION MASS_2/DESCRIPTION --- MASS_1/DESCRIPTION 2021-05-03 10:03:00.000000000 +0100 +++ MASS_2/DESCRIPTION 2021-05-03 10:03:50.000000000 +0100 @@ -33,4 +33,4 @@ David Firth [ctb] Maintainer: Brian Ripley <rip...@stats.ox.ac.uk> Repository: CRAN -Date/Publication: 2021-05-03 09:03:00 UTC +Date/Publication: 2021-05-03 09:03:50 UTC diff -Naur MASS_1/MD5 MASS_2/MD5 --- MASS_1/MD5 2021-05-03 10:03:00.000000000 +0100 +++ MASS_2/MD5 2021-05-03 10:03:50.000000000 +0100 @@ -1,4 +1,4 @@ -560f72bfd93ac57532d2cf113078d2e7 *DESCRIPTION +ecf84f78aac3c625898be45513307d79 *DESCRIPTION 35aff05a505ecf7e81e0473767794ca9 *INDEX c7acdc0fa828f781a0a5586ab9d4fa1b *LICENCE.note 0ac7b30ad35a4c19ea69d76a6a366b02 *NAMESPACE Please prevent SHA changes of released packages on CRAN. Once a package is released, it should not be touched again. -- Stefano Borini Principal Analytical Tools Developer AstraZeneca R&D BioPharmaceuticals | Data Science & AI | Early Biometrics & Statistical Innovation ________________________________ AstraZeneca UK Limited is a company incorporated in England and Wales with registered number:03674842 and its registered office at 1 Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0AA. This e-mail and its attachments are intended for the above named recipient only and may contain confidential and privileged information. If they have come to you in error, you must not copy or show them to anyone; instead, please reply to this e-mail, highlighting the error to the sender and then immediately delete the message. For information about how AstraZeneca UK Limited and its affiliates may process information, personal data and monitor communications, please see our privacy notice at www.astrazeneca.com<https://www.astrazeneca.com> ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel