Your output and comments do not match what should happen when installing a regular package.
$ sudo pacman -Syu r
:: Synchronizing package databases...
core is up to date
extra is up to date
multilib is up to date
:: Starting full system upgrade...
resolving dependencies...
looking for conflicting packages...
Packages (1) r-4.3.2-4
Total Download Size: 44.32 MiB
Total Installed Size: 70.36 MiB
:: Proceed with installation? [Y/n]
:: Retrieving packages...
r-4.3.2-4-x86_64 44.3 MiB 9.73 MiB/s 00:05 [##################################################################] 100%
(1/1) checking keys in keyring [##################################################################] 100%
(1/1) checking package integrity [##################################################################] 100%
(1/1) loading package files [##################################################################] 100%
(1/1) checking for file conflicts [##################################################################] 100%
(1/1) checking available disk space [##################################################################] 100%
:: Processing package changes...
(1/1) installing r [##################################################################] 100%
Optional dependencies for r
blas-openblas: faster linear algebra
gcc-fortran: needed to compile some CRAN packages
texlive-latex: latex sty files
:: Running post-transaction hooks...
(1/3) Arming ConditionNeedsUpdate...
(2/3) Updating the info directory file...
(3/3) Updating the desktop file MIME type cache...
Which obviously also worked here … so please try to better explain your situation.
PSs
Again, should not matter. If they were actually using pacman then it would not be compiling a darn thing.
Someone is not telling the truth