I use latest cmdstanr and noticed a new release had been issued. Running as usual in terminal leads to:
> install_cmdstan(cores = 4)
The CmdStan toolchain is setup properly!
* Latest CmdStan release is v2.26.1
* Installing CmdStan v2.26.1 in /Users/torkarr/.cmdstanr/cmdstan-2.26.1
* Downloading cmdstan-2.26.1.tar.gz from GitHub...
Error: Download of CmdStan failed. Please try again.
Taking the link from the release page leads to this instead,
> install_cmdstan(cores = 4, release_url = "https://github.com/stan-dev/cmdstan/archive/v2.26.1.tar.gz")
The CmdStan toolchain is setup properly!
* Installing CmdStan from https://github.com/stan-dev/cmdstan/archive/v2.26.1.tar.gz
* Download complete
* Unpacking archive...
* Building CmdStan binaries...
curl -L https://github.com/stan-dev/stanc3/releases/download/nightly/mac-stanc -o bin/stanc --retry 5 --retry-delay 10
clang++ -c -fvisibility=hidden -o bin/cmdstan/stansummary.o src/cmdstan/stansummary.cpp
clang++ -c -fvisibility=hidden -o bin/cmdstan/print.o src/cmdstan/print.cpp
clang++ -c -fvisibility=hidden -o bin/cmdstan/diagnose.o src/cmdstan/diagnose.cpp
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0src/cmdstan/stansummary.cpp:1:10: fatal error: 'cmdstan/stansummary_helper.hpp' file not found
src/cmdstan/print.cpp:1src/cmdstan/diagnose.cpp:1:10:10: fatal error: :'cmdstan/stansummary_helper.hpp' file not found
fatal error: 'cmdstan/print_helper.hpp' file not found
#include <cmdstan/stansummary_helper.hpp>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <cmdstan/stansummary_helper.hpp>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#include <cmdstan/print_helper.hpp>
^~~~~~~~~~~~~~~~~~~~~~~~~~
100 617 100 617 0 0 2091 0 --:--:-- --:--:-- --:--:-- 2098
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 01 error generated.
make: *** [bin/cmdstan/diagnose.o] Error 1
make: *** Waiting for unfinished jobs....
1 error generated.
1 error generated.
make: *** [bin/cmdstan/print.o] Error 1
make: *** [bin/cmdstan/stansummary.o] Error 1
100 10.5M 100 10.5M 0 0 8975k 0 0:00:01 0:00:01 --:--:-- 15.1M
chmod +x bin/stanc
Warning message:
There was a problem during installation. See the error message(s) above. 
I use latest
cmdstanrand noticed a new release had been issued. Running as usual in terminal leads to:Taking the link from the release page leads to this instead,