I think I changed something in the stan directory accidentally. I am trying to rebuild cmdstan and it is giving me the following error message

I ran this

```
install_cmdstan(cores = 2, overwrite = T)
```

And I got the following error

```
--- Compiling the main object file. This might take up to a minute. ---
clang++ -Wno-deprecated-declarations -std=c++17 -Wno-unknown-warning-option -Wno-tautological-compare -Wno-sign-compare -D_REENTRANT -ffp-contract=off -Wno-ignored-attributes -I stan/lib/stan_math/lib/tbb_2020.3/include -O3 -I src -I stan/src -I stan/lib/rapidjson_1.1.0/ -I lib/CLI11-1.9.1/ -I stan/lib/stan_math/ -I stan/lib/stan_math/lib/eigen_3.4.0 -I stan/lib/stan_math/lib/boost_1.84.0 -I stan/lib/stan_math/lib/sundials_6.1.1/include -I stan/lib/stan_math/lib/sundials_6.1.1/src/sundials -DBOOST_DISABLE_ASSERTS -c -o src/cmdstan/main.o src/cmdstan/main.cpp
In file included from src/cmdstan/main.cpp:1:
In file included from src/cmdstan/command.hpp:4:
In file included from src/cmdstan/arguments/arg_data.hpp:4:
In file included from src/cmdstan/arguments/categorical_argument.hpp:4:
In file included from src/cmdstan/arguments/argument.hpp:4:
In file included from stan/src/stan/callbacks/writer.hpp:4:
In file included from stan/lib/stan_math/stan/math/prim/fun/Eigen.hpp:22:
In file included from stan/lib/stan_math/lib/eigen_3.4.0/Eigen/Dense:1:
In file included from stan/lib/stan_math/lib/eigen_3.4.0/Eigen/Core:19:
stan/lib/stan_math/lib/eigen_3.4.0/Eigen/src/Core/util/Macros.h:679:10: fatal error: 'cmath' file not found
679 | #include <cmath>
| ^~~~~~~
--- Compiling pre-compiled header. This might take a few seconds. ---
clang++ -Wno-deprecated-declarations -std=c++17 -Wno-unknown-warning-option -Wno-tautological-compare -Wno-sign-compare -D_REENTRANT -ffp-contract=off -Wno-ignored-attributes -I stan/lib/stan_math/lib/tbb_2020.3/include -O3 -I src -I stan/src -I stan/lib/rapidjson_1.1.0/ -I lib/CLI11-1.9.1/ -I stan/lib/stan_math/ -I stan/lib/stan_math/lib/eigen_3.4.0 -I stan/lib/stan_math/lib/boost_1.84.0 -I stan/lib/stan_math/lib/sundials_6.1.1/include -I stan/lib/stan_math/lib/sundials_6.1.1/src/sundials -DBOOST_DISABLE_ASSERTS -c stan/src/stan/model/model_header.hpp -o stan/src/stan/model/model_header.hpp.gch/model_header_16_0.hpp.gch
In file included from stan/src/stan/model/model_header.hpp:4:
In file included from stan/lib/stan_math/stan/math.hpp:19:
In file included from stan/lib/stan_math/stan/math/rev.hpp:4:
In file included from stan/lib/stan_math/stan/math/prim/fun/Eigen.hpp:22:
In file included from stan/lib/stan_math/lib/eigen_3.4.0/Eigen/Dense:1:
In file included from stan/lib/stan_math/lib/eigen_3.4.0/Eigen/Core:19:
stan/lib/stan_math/lib/eigen_3.4.0/Eigen/src/Core/util/Macros.h:679:10: fatal error: 'cmath' file not found
679 | #include <cmath>
| ^~~~~~~
1 error generated.
make: *** [stan/src/stan/model/model_header.hpp.gch/model_header_16_0.hpp.gch] Error 1
make: *** Waiting for unfinished jobs....
1 error generated.
make: *** [src/cmdstan/main.o] Error 1
Warning message:
There was a problem during installation. See the error message(s) above.
```

Does someone has any idea on how to fix this?