[R-pkg-team] Bug#980809: Matrix package default tolerance on s390x (Re: Bug#980809: rmatrix: breaks autopkgtest of r-cran-glmmtmb on s390x)

[Dirk Eddelbuettel]

Martin,

I have this long-running bug report against Matrix, triggered by glmmTMB on
s390x.  Graham has been chasing this patiently and we are now at the level of
checking on a shell account on the appropriate hardware. 

We validated that everything does in fact "still break" with CRAN-current
packages of everything (and R 4.0.3, I guess by tomorrow we'd have 4.0.4).

glmmTMB does indeed fail in an example -- but so does Matrix 1.3-2 when I run

  _R_CHECK_FORCE_SUGGESTS_=false R CMD check \
                     --no-manual --no-vignettes Matrix_1.3-2.tar.gz

and I see

  [...]
  Running 'factorizing.R'
 ERROR
Running the tests in 'tests/factorizing.R' failed.
Last 13 lines of output:
  +     inherits(qrZ, "sparseQR")
  +     inherits(Rz, "sparseMatrix")
  +     isTriangular(Rz)
  +     isDiagonal(Rz) # even though formally a "dtCMatrix"
  +     qr2rankMatrix(qrZ, do.warn=FALSE) == 6
  + })
  > options(oo)
  > 
  > ## problematic rank deficient rankMatrix() case -- only seen in large cases ??
  > Z. <- readRDS(system.file("external", "Z_NA_rnk.rds", package="Matrix"))
  > tools::assertWarning(rnkZ. <- rankMatrix(Z., method = "qr")) # gave errors
  Error in assertCondition(expr, classes, .exprString = d.expr) : 
    Failed to get warning in evaluating rnkZ. <- rankMatrix(Z., method  ...
  Calls: <Anonymous> -> assertCondition
  Execution halted
* checking for unstated dependencies in vignettes ... OK

Can you advise if I should dive into a particular routine or comparison to
see what is up here?

Best,  Dirk

-- 
https://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org