Test R 4.0 on CI (#3961)

Author: yutannihilation

.github/workflows/R-CMD-check.yaml

@@ -22,14 +22,15 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: windows-latest, r: '3.6', vdiffr: true}
-          - {os: macOS-latest, r: '3.6', vdiffr: true}
-          - {os: macOS-latest, r: 'devel', vdiffr: false}
-          - {os: ubuntu-16.04, r: '3.2', vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
-          - {os: ubuntu-16.04, r: '3.3', vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
-          - {os: ubuntu-16.04, r: '3.4', vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
-          - {os: ubuntu-16.04, r: '3.5', vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
-          - {os: ubuntu-16.04, r: '3.6', vdiffr: true, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: windows-latest, r: '4.0',   vdiffr: true}
+          - {os: macOS-latest,   r: '4.0',   vdiffr: true}
+          - {os: macOS-latest,   r: 'devel', vdiffr: false}
+          - {os: ubuntu-16.04,   r: '4.0',   vdiffr: true,  cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: '3.6',   vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: '3.5',   vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: '3.4',   vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: '3.3',   vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: '3.2',   vdiffr: false, cran: "https://demo.rstudiopm.com/all/__linux__/xenial/latest"}
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
@@ -68,6 +69,10 @@ jobs:
         env:
           RHUB_PLATFORM: linux-x86_64-ubuntu-gcc
         run: |
+          # Use cran:libgit2 PPA to avoid conflicts of libcurl4-gnutls-dev
+          # Remove this after https://github.com/r-lib/actions/pull/97 gets merged
+          sudo add-apt-repository ppa:cran/libgit2
+
           Rscript -e "remotes::install_github('r-hub/sysreqs')"
           sysreqs=$(Rscript -e "cat(sysreqs::sysreq_commands('DESCRIPTION'))")
           sudo -s eval "$sysreqs"
@@ -90,13 +95,6 @@ jobs:
             brew install udunits gdal
           fi
 
-      # TODO: Remove this when https://github.com/r-lib/xml2/issues/296 is fixed on CRAN
-      - name: Install the dev version of xml2 as a workaround
-        if: runner.os == 'macOS' && matrix.config.r == 'devel'
-        run: |
-          remotes::install_github('r-lib/xml2')
-        shell: Rscript {0}
-
       - name: Install dependencies
         run: |
           remotes::install_deps(dependencies = TRUE)

.travis.yml

@@ -11,6 +11,7 @@ matrix:
     env:
       - VDIFFR_RUN_TESTS=true
       - VDIFFR_LOG_PATH="../vdiffr.Rout.fail"
+  - r: 3.6
   - r: 3.5
   - r: 3.4
   - r: 3.3