Specifying intial values failed for brms with cmdstanr backend (but not rstan backend)

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The main question: init= in brms does not seem to work with cmdstanr backend (while it works with rstan backend).

Session info:
R version 4.3.2 (2023-10-31)
Platform: aarch64-apple-darwin20 (64-bit)
Running under: macOS Sonoma 14.2.1
brms_2.20.4
CmdStan version: 2.33.1
cmdstanr: 0.6.1


The following is a minimal example.

The data is available here; load the data as df_tmp.

First, set formula, priors, and initial values:

library(tidyverse)
library(brms)

# formula
bf_tmp <- bf(RT | dec(Response) ~ 0 + IV +
                (0 + IV | Subject),
            bs ~ 0 + IV +
                (0 + IV | Subject),
            ndt ~ 0 + IV +
                (0 + IV | Subject),
            bias ~ 0 + IV +
                (0 + IV | Subject))

# priors
prior_tmp <- c(prior(normal(0, 5), class = b), # -10 ~ 0 ~ 10
            prior(normal(0, 5), class = sd),
            
            # log() 0.6 ~ 1.65 ~ 4.48
            prior(normal(0.5, 0.5), class = b, dpar = bs), 
            prior(normal(0, 0.5), class = sd, dpar = bs),
            
            # log() 0.045 ~ 0.1 ~ 0.2
            prior(normal(-2.3, 0.4), class = b, dpar = ndt), 
            prior(normal(0, 0.5), class = sd, dpar = ndt),
            
            # logit 0.05 ~ 0.5 ~ 0.95
            prior(normal(0, 1.5), class = b, dpar = bias), 
            prior(normal(0.5, 0.5), class = sd, dpar = bias),
            prior(lkj(2), class = cor))

# initial values
tmp_ddm <- make_standata(bf_tmp, 
                         data = df_tmp, 
                         family = wiener(),
                         prior = prior_tmp)
initfun <- function() {
    list(
        b = rnorm(tmp_ddm$K),
        b_bs = runif(tmp_ddm$K_bs, 0.3, 1), # exp(0.3)=1.35; exp(1)=2.72
        b_ndt = runif(tmp_ddm$K_ndt, -2.3, -1.7), # exp(-2.3)=0.1; exp(-1.7)=0.18
        b_bias = rnorm(tmp_ddm$K_bias, 0, 0.25), # plogis(-0.5)=0.38; plogis(0.5)=0.62
        sd_1 = runif(tmp_ddm$M_1, 0.5, 1),
        z_1 = matrix(rnorm(tmp_ddm$M_1*tmp_ddm$N_1, 0, 0.01),
                     tmp_ddm$M_1, tmp_ddm$N_1),
        L_1 = diag(tmp_ddm$M_1)
    )
}

Use init with rstan backend:

# this fitting works
brmsfit1 <- 
    brm(formula = bf_tmp,  
        data = df_tmp, 
        family = wiener(), 
        prior = prior_tmp, 
        init = initfun,
        sample_prior = "no",  
        save_pars = save_pars(all = TRUE),    
        backend = "rstan",
        cores = 2, 
        chains = 2, 
        iter = 4000,
        warmup = 2000)

The fitting works though there are some initial value failures. (BTW, without setting the initial values, the model hardly work.) The output is:

Compiling Stan program...
recompiling to avoid crashing R session
Start sampling
starting worker pid=36726 on localhost:11963 at 12:22:45.726
starting worker pid=36739 on localhost:11963 at 12:22:45.801

SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 1).
Chain 1: 
Chain 1: Gradient evaluation took 0.001733 seconds
Chain 1: 1000 transitions using 10 leapfrog steps per transition would take 17.33 seconds.
Chain 1: Adjust your expectations accordingly!
Chain 1: 
Chain 1: 

SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 2).
Chain 2: Rejecting initial value:
Chain 2:   Log probability evaluates to log(0), i.e. negative infinity.
Chain 2:   Stan can't start sampling from this initial value.
Chain 2: Rejecting initial value:
Chain 2:   Log probability evaluates to log(0), i.e. negative infinity.
Chain 2:   Stan can't start sampling from this initial value.
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.578, but must be greater than nondecision time = 0.596261 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.769, but must be greater than nondecision time = 0.882417 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.854, but must be greater than nondecision time = 0.979366 (in 'anon_model', line 29, column 7 to column 55) (in 'anon_model', line 29, column 7 to column 55)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.854, but must be greater than nondecision time = 0.897329 (in 'anon_model', line 29, column 7 to column 55) (in 'anon_model', line 29, column 7 to column 55)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 2.703, but must be greater than nondecision time = 2503.47 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: Rejecting initial value:
Chain 2:   Log probability evaluates to log(0), i.e. negative infinity.
Chain 2:   Stan can't start sampling from this initial value.
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.836, but must be greater than nondecision time = 1.15877 (in 'anon_model', line 29, column 7 to column 55) (in 'anon_model', line 29, column 7 to column 55)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.902, but must be greater than nondecision time = 1.08415 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 1.215, but must be greater than nondecision time = 21.3303 (in 'anon_model', line 29, column 7 to column 55) (in 'anon_model', line 29, column 7 to column 55)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 0.394, but must be greater than nondecision time = 0.414266 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: Rejecting initial value:
Chain 2:   Error evaluating the log probability at the initial value.
Chain 2: Exception: Exception: wiener_lpdf: Random variable  = 3.439, but must be greater than nondecision time = 1951.71 (in 'anon_model', line 31, column 7 to column 61) (in 'anon_model', line 31, column 7 to column 61)
Chain 2: 
Chain 2: Gradient evaluation took 0.001758 seconds
Chain 2: 1000 transitions using 10 leapfrog steps per transition would take 17.58 seconds.
Chain 2: Adjust your expectations accordingly!
Chain 2: 
Chain 2: 
Chain 2: Iteration:    1 / 4000 [  0%]  (Warmup)
Chain 1: Iteration:    1 / 4000 [  0%]  (Warmup)

Use init with cmdstanr backend:

# this fitting does not work
brmsfit2 <- 
    brm(formula = bf_tmp,  
        data = df_tmp, 
        family = wiener(), 
        prior = prior_tmp, 
        init = initfun,
        sample_prior = "no",  
        save_pars = save_pars(all = TRUE),    
        backend = "cmdstanr",
        cores = 2, 
        chains = 2, 
        iter = 4000,
        warmup = 2000)

The output is (it does not work):

Compiling Stan program...
In file included from /var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.hpp:1:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/src/stan/model/model_header.hpp:4:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math.hpp:19:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math/rev.hpp:10:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math/rev/fun.hpp:200:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math/prim/functor.hpp:16:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math/prim/functor/integrate_ode_rk45.hpp:6:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/stan/math/prim/functor/ode_rk45.hpp:9:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/numeric/odeint.hpp:76:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/numeric/odeint/integrate/observer_collection.hpp:23:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/function.hpp:30:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/function/detail/prologue.hpp:17:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/function/function_base.hpp:21:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/type_index.hpp:29:
In file included from /Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/type_index/stl_type_index.hpp:47:
/Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/container_hash/hash.hpp:132:33: warning: 'unary_function<const std::
error_category *, unsigned long>' is deprecated [-Wdeprecated-declarations]
        struct hash_base : std::unary_function<T, std::size_t> {};
                                ^
/Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/container_hash/hash.hpp:692:18: note: in instantiation of template class 'boost::hash_detail::hash_base<const std::error_category *>' requested here
        : public boost::hash_detail::hash_base<T*>
                 ^
/Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/container_hash/hash.hpp:420:24: note: in instantiation of template class 'boost::hash<const std::error_category *>' requested here
        boost::hash<T> hasher;
                       ^
/Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/boost_1.78.0/boost/container_hash/hash.hpp:551:9: note: in instantiation of function template specialization 'boost::hash_combine<const std::error_category *>' requested here
        hash_combine(seed, &v.category());
        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__functional/unary_function.h:23:29: note: 'unary_function<const std::error_category *, unsigned long>' has been explicitly marked deprecated here
struct _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 unary_function
                            ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:
850:41: note: expanded from macro '_LIBCPP_DEPRECATED_IN_CXX11'
#    define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
                                        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:835:49: note: expanded from macro '_LIBCPP_DEPRECATED'
#      define _LIBCPP_DEPRECATED __attribute__((deprecated))
                                                ^

1 warning generated.

ld: warning: duplicate -rpath '/Users/username/.cmdstan/cmdstan-2.33.1/stan/lib/stan_math/lib/tbb' ignored

Start sampling
Init values were only set for a subset of parameters. 
Missing init values for the following parameters:
 - chain 1: sd_2, z_2, L_2, sd_3, z_3, L_3, sd_4, z_4, L_4
 - chain 2: sd_2, z_2, L_2, sd_3, z_3, L_3, sd_4, z_4, L_4

Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.767, but must be greater than nondecision time = 2.81678 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 3.439, but must be greater than nondecision time = 15.0146 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 1.083, but must be greater than nondecision time = 1.35109 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 1.083, but must be greater than nondecision time = 2.83071 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.836, but must be greater than nondecision time = 535.14 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 29, column 6 to column 54) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.836, but must be greater than nondecision time = 1.08043 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 29, column 6 to column 54) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.788, but must be greater than nondecision time = 0.795229 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.394, but must be greater than nondecision time = 0.450659 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.554, but must be greater than nondecision time = 0.758174 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 1.005, but must be greater than nondecision time = 1.12468 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Boundary separation is 0, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Boundary separation is 0, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Nondecision time is 0, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
... (repeat Chain 1 warning)
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Boundary separation is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Boundary separation is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 3.32, but must be greater than nondecision time = 30.9597 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Boundary separation is 0, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Boundary separation is 0, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Nondecision time is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Nondecision time is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Random variable  = 3.32, but must be greater than nondecision time = 54.672 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Random variable  = 1.58, but must be greater than nondecision time = 1.76449 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Boundary separation is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Boundary separation is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Nondecision time is inf, but must be positive finite! (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 2 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 2 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.633, but must be greater than nondecision time = 0.67182 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 1 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 1 Exception: Exception: wiener_lpdf: Random variable  = 0.689, but must be greater than nondecision time = 0.69264 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 1 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,
Chain 1 but if this warning occurs often then your model may be either severely ill-conditioned or misspecified.
Chain 1 
Chain 2 Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Chain 2 Exception: Exception: wiener_lpdf: Random variable  = 0.394, but must be greater than nondecision time = 0.394988 (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 31, column 6 to column 59) (in '/var/folders/57/nj9j4lzj3vz1m13h4yz87b180000gn/T/RtmpwZFqBw/model-81bc78776a98.stan', line 187, column 6 to column 84)
Chain 2 If this warning occurs sporadically, such as for highly constrained variable types like covariance matrices, then the sampler is fine,

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