Build fails on ubuntu-20.04(devel)

Hi,
I am using GitHub Actions to check the build of an R package on Ubuntu, macOS and Windows. The Build fails in one of the runners (ubuntu-20.04 (devel)):
Screenshot 2021-01-10 at 14.20.29

Run rcmdcheck::rcmdcheck(args = c("--no-manual", "--as-cran"), error_on = "warning", check_dir = "check")
── R CMD build ─────────────────────────────────────────────────────────────────
* checking for file ‘.../DESCRIPTION’ ... OK
* preparing ‘TreeSummarizedExperiment’:
* checking DESCRIPTION meta-information ... OK
* installing the package to build vignettes
      -----------------------------------
ERROR: dependencies ‘SingleCellExperiment’, ‘SummarizedExperiment’ are not available for package ‘TreeSummarizedExperiment’
* removing ‘/tmp/Rtmpma3sVt/Rinst567e71f0188/TreeSummarizedExperiment’
      -----------------------------------
ERROR: package installation failed
Error: Error in proc$get_built_file() : Build process failed
Calls: <Anonymous> ... build_package -> with_envvar -> force -> <Anonymous>
Execution halted
Error: Process completed with exit code 1.

This is the branch the error occurs: https://github.com/fionarhuang/TreeSummarizedExperiment/tree/CI-1

Anyone have any idea how this can be fixed?
Thanks!