Dear RSTAN community,

I’m running into compilation errors when calling a model through brms on my institute’s cluster. Any hints much appreciated!

```
Compilation ERROR, function(s)/method(s) not created!
Error in compileCode(f, code, language = language, verbose = verbose) :
instantiation of "T__ modela3e1f19e59e_1bcd7d12e8e907f753fd6fd08f4500ed_namespace::modela3e1f19e59e_1bcd7d12e8e907f753fd6fd08f4500ed::log_prob<propto__,jacobian__,T__>(std::vector<T__, std::allocator<T__>> &, std::vector<int, std::allocator<int>> &, std::ostream *) const [with propto__=false, jacobian__=false, T__=stan::math::var]" at line 950 of "filea3e113e2ecaa.cpp" instantiation of "T_ modela3e1f19e59e_1bcd7d12e8e907f753fd6fd08f4500ed_namespace::modela3e1f19e59e_1bcd7d12e8e907f753fd6fd08f4500ed::log_prob<propto,jacobian,T_>(Eigen::Matrix<T_, -1, 1, 0, -1, 1> &, std::ostream *) const [with propto=false, jacobian=false, T_=stan::math::var]" at line 96 of "/p/projects/rd3mod/R/libraries/3.6.3/StanHeaders/include/src/stan/model/model_base_crtp.hpp" instantiation of "stan::math::var stan::model::model_base_crtp<M>::log_prob(Eigen::Matrix<stan::math::var, -1, 1, 0, -1, 1> &, std::ostream *) const [with M=modela3e1f19e59e_1bcd7d12e8e907f753fd6fd
```

- Operating System: SUSE Linux Enterprise Server Version 12, Release Level 3
- R version: 3.6.3
- rstan version: 2.21.2
- brms Version: 2.15