* using log directory ‘/data/localhost/ripley/R/packages/tests-BLIS/AdsorpR.Rcheck’
* using R Under development (unstable) (2026-08-27 r90452)
* using platform: x86_64-pc-linux-gnu
* R was compiled by
    gcc (GCC) 16.2.1 20260819 (Red Hat 16.2.1-2)
    GNU Fortran (GCC) 16.2.1 20260819 (Red Hat 16.2.1-2)
* running under: Fedora Linux 44 (Server Edition)
* using session charset: UTF-8
* current time: 2026-08-31 07:49:22 UTC
* using option ‘--no-stop-on-test-error’
* checking for file ‘AdsorpR/DESCRIPTION’ ... OK
* checking extension type ... Package
* this is package ‘AdsorpR’ version ‘0.1.0’
* package encoding: UTF-8
* checking package namespace information ... OK
* checking package dependencies ... OK
* checking if this is a source package ... OK
* checking if there is a namespace ... OK
* checking for executable files ... OK
* checking for hidden files and directories ... OK
* checking for portable file names ... OK
* checking for sufficient/correct file permissions ... OK
* checking whether package ‘AdsorpR’ can be installed ... OK
* checking package directory ... OK
* checking ‘build’ directory ... OK
* checking DESCRIPTION meta-information ... OK
* checking top-level files ... OK
* checking for left-over files ... OK
* checking index information ... OK
* checking package subdirectories ... OK
* checking code files for non-ASCII characters ... OK
* checking R files for syntax errors ... OK
* checking whether the package can be loaded ... OK
* checking whether the package can be loaded with stated dependencies ... OK
* checking whether the package can be unloaded cleanly ... OK
* checking whether the namespace can be loaded with stated dependencies ... OK
* checking whether the namespace can be unloaded cleanly ... OK
* checking loading without being on the library search path ... OK
* checking use of S3 registration ... OK
* checking dependencies in R code ... OK
* checking S3 generic/method consistency ... OK
* checking replacement functions ... OK
* checking foreign function calls ... OK
* checking R code for possible problems ... OK
* checking Rd files ... OK
* checking Rd metadata ... OK
* checking Rd line widths ... OK
* checking Rd cross-references ... OK
* checking for missing documentation entries ... OK
* checking for code/documentation mismatches ... OK
* checking Rd \usage sections ... OK
* checking Rd contents ... OK
* checking for unstated dependencies in examples ... OK
* checking installed files from ‘inst/doc’ ... OK
* checking files in ‘vignettes’ ... OK
* checking examples ... ERROR
Running examples in ‘AdsorpR-Ex.R’ failed
The error most likely occurred in:

> ### Name: nonlinear_bet
> ### Title: Non-linear BET Model
> ### Aliases: nonlinear_bet
> 
> ### ** Examples
> 
> Ce <- c(1, 2.5, 4, 5.5, 7)
> Qe <- c(0.4, 1.0, 1.7, 2.3, 2.7)
> result <- nonlinear_bet(Ce, Qe)
Warning in nls(Qe ~ (Qm * Cb * Ce)/((Cs - Ce) * (1 + (Cb - 1) * Ce/Cs)),  :
  singular gradient
Error in chol2inv(object$m$Rmat()) : 
  element (2, 2) is zero, so the inverse cannot be computed
Calls: nonlinear_bet -> summary -> summary.nls -> chol2inv
Execution halted
* checking for unstated dependencies in ‘tests’ ... OK
* checking tests ...
  Running ‘testthat.R’
 OK
* checking for unstated dependencies in vignettes ... OK
* checking package vignettes ... OK
* checking re-building of vignette outputs ... [11s/12s] ERROR
Error(s) in re-building vignettes:
--- re-building ‘AdsorpR-vignette.Rmd’ using rmarkdown

Quitting from AdsorpR-vignette.Rmd:114-123 [unnamed-chunk-3]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<error/rlang_error>
Error in `chol2inv()`:
! element (2, 2) is zero, so the inverse cannot be computed
---
Backtrace:
    ▆
 1. └─AdsorpR::nonlinear_bet(Ce, Qe)
 2.   ├─base::summary(model)
 3.   └─stats:::summary.nls(model)
 4.     └─base::chol2inv(object$m$Rmat())
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'AdsorpR-vignette.Rmd' failed with diagnostics:
element (2, 2) is zero, so the inverse cannot be computed
--- failed re-building ‘AdsorpR-vignette.Rmd’

SUMMARY: processing the following file failed:
  ‘AdsorpR-vignette.Rmd’

Error: Vignette re-building failed.
Execution halted

* checking PDF version of manual ... OK
* checking HTML version of manual ... OK
* checking for non-standard things in the check directory ... OK
* checking for detritus in the temp directory ... OK
* DONE

Status: 2 ERRORs
See
  ‘/data/localhost/ripley/R/packages/tests-BLIS/AdsorpR.Rcheck/00check.log’
for details.

Command exited with non-zero status 1
Time 1:00.68, 49.15 + 6.14