I have been trying to install the package pcaGoPromoter but I am having trouble doing so.

> BiocManager::install("pcaGoPromoter")
Bioconductor version 3.12 (BiocManager 1.30.10), R 4.0.3 (2020-10-10)
Installing package(s) 'pcaGoPromoter'
Warning message:
package ‘pcaGoPromoter’ is not available for this version of R

A version of this package for your version of R might be available elsewhere,
see the ideas at
https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages

Any ideas what is going wrong here?

> sessionInfo( )
R version 4.0.3 (2020-10-10)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Debian GNU/Linux bullseye/sid

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.9.0

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8       
 [4] LC_COLLATE=en_US.UTF-8     LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
[10] LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] BiocManager_1.30.10 compiler_4.0.3      tools_4.0.3

Thank you very much!

The notification says that the package pcaGoPromoter has been removed from Bioconductor starting from the current release (i.e. Bioconductor 3.12), and can thus not be installed. See the Bioconductor release notes here. If you would install/use a (the) previous version of Bioconductor, then this package likely will be available. If you go this way, be sure to use the correct / compatible version of R as well! Yet I would recommend to find an alternative package that has same functionality but is current. There is of course a reason the package has been removed, likely because it wasn't maintained anymore.