"Global state has changed" warning

[rempsyc]

Transferred from paul-buerkner/brms#1670

---

We rely on brms / rstan in the report package, and we have a workflow checking for warnings in tests. The workflow is failing due to a warning caused by brms / rstan (see easystats/report#448),

Global state has changed

Essentially, the warning seems to arise from a test simply calling the brms::brms() function as below:

model <- suppressMessages(suppressWarnings(brms::brm(
    mpg ~ qsec + wt,data = mtcars, refresh = 0, iter = 1, seed = 333)))

Generates that "Global state has changed" warning. The detailed error from the workflow is available e.g., here: https://github.com/easystats/report/actions/runs/9797434007/job/27054023826?pr=447#step:5:196

── Warning (test-report.brmsfit.R:3:1): report.brms ────────────────────────────
Global state has changed:
     names(before[[4]])                | names(after[[4]])                      
[94] "PIPX_HOME"                       | "PIPX_HOME"                       [94] 
[95] "PKGCACHE_HTTP_VERSION"           | "PKGCACHE_HTTP_VERSION"           [95] 
[96] "PKGLOAD_PARENT_TEMPDIR"          | "PKGLOAD_PARENT_TEMPDIR"          [96] 
                                       - "PKG_CPPFLAGS"                    [97] 
                                       - "PKG_LIBS"                        [98] 
[97] "POWERSHELL_DISTRIBUTION_CHANNEL" | "POWERSHELL_DISTRIBUTION_CHANNEL" [99] 
[98] "PWD"                             | "PWD"                             [100]
[99] "RENV_CONFIG_REPOS_OVERRIDE"      | "RENV_CONFIG_REPOS_OVERRIDE"      [101]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
      names(before[[4]])        | names(after[[4]])              
[153] "TESTTHAT"                | "TESTTHAT"                [155]
[154] "TZ"                      | "TZ"                      [156]
[155] "USER"                    | "USER"                    [157]
                                - "USE_CXX17"               [158]
[156] "VCPKG_INSTALLATION_ROOT" | "VCPKG_INSTALLATION_ROOT" [159]
[157] "XDG_CONFIG_HOME"         | "XDG_CONFIG_HOME"         [160]
[158] "XDG_RUNTIME_DIR"         | "XDG_RUNTIME_DIR"         [161]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
before[[4]][94:99] vs after[[4]][94:101]
  PIPX_BIN_DIR"/opt/pipx_bin"
  PIPX_HOME"/opt/pipx"
  PKGCACHE_HTTP_VERSION"2"
  PKGLOAD_PARENT_TEMPDIR"/tmp/RtmpQHAqXH"
+ PKG_CPPFLAGS"  -I\"/home/runner/work/_temp/Library/Rcpp/include/\"  -I\"/home/runner/work/_temp/Library/RcppEigen/include/\"  -I\"/home/runner/work/_temp/Library/RcppEigen/include/unsupported\"  -I\"/home/runner/work/_temp/Library/BH/include\" -I\"/home/runner/work/_temp/Library/StanHeaders/include/src/\"  -I\"/home/runner/work/_temp/Library/StanHeaders/include/\"  -I\"/home/runner/work/_temp/Library/RcppParallel/include/\"  -I\"/home/runner/work/_temp/Library/rstan/include\" -DEIGEN_NO_DEBUG  -DBOOST_DISABLE_ASSERTS  -DBOOST_PENDING_INTEGER_LOG2_HPP  -DSTAN_THREADS  -DUSE_STANC3 -DSTRICT_R_HEADERS  -DBOOST_PHOENIX_NO_VARIADIC_EXPRESSION  -D_HAS_AUTO_PTR_ETC=0  -include '/home/runner/work/_temp/Library/StanHeaders/include/stan/math/prim/fun/Eigen.hpp'  -D_REENTRANT -DRCPP_PARALLEL_USE_TBB=1 "
+ PKG_LIBS" '/home/runner/work/_temp/Library/rstan/lib//libStanServices.a' -L'/home/runner/work/_temp/Library/StanHeaders/lib/' -lStanHeaders -L'/home/runner/work/_temp/Library/RcppParallel/lib/' -ltbb "
  POWERSHELL_DISTRIBUTION_CHANNEL"GitHub-Actions-ubuntu22"
  PWD"/home/runner/work/report/report"
  RENV_CONFIG_REPOS_OVERRIDE"https://packagemanager.posit.co/cran/__linux__/jammy/latest"
      before[[4]]              | after[[4]]                    
[153] "true"                   | "true"                   [155]
[154] "UTC"                    | "UTC"                    [156]
[155] "runner"                 | "runner"                 [157]
                               - "1"                      [158]
[156] "/usr/local/share/vcpkg" | "/usr/local/share/vcpkg" [159]
[157] "/home/runner/.config"   | "/home/runner/.config"   [160]
[158] "/run/user/1001"         | "/run/user/1001"         [161]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

The brms maintainer suggested that this might have to do with rstan and not brms. Would you have any idea as to how we can fix this on our end, or is this something that needs fixing in rstan or in some of its dependencies?