simulate_network() fails

[famuvie]

From the first example in the help page:

library(GERGM)
#> GERGM: Generalized Exponential Random Graph Models
#> Version 0.13.0 created on 2018-05-14.
#> copyright (c) 2018, Matthew J. Denny, Penn State University
#>                     James D. Wilson, University of San Francisco
#>                     Skyler Cranmer, Ohio State University
#>                     Bruce A. Desmarais, Penn State University
#>                     Shankar Bhamidi, University of North Carolina
#> Type help('gergm') to get started.
#> Development website: https://github.com/matthewjdenny/GERGM
set.seed(12345)
net <- matrix(runif(100),10,10)
diag(net) <- 0
colnames(net) <- rownames(net) <- letters[1:10]
formula <- net ~ edges + ttriads + in2stars

test <- simulate_networks(formula,
 thetas = c(0.6,-0.8),
 lambdas = 0.2,
 number_of_networks_to_simulate = 100,
 thin = 1/10,
 proposal_variance = 0.5,
 MCMC_burnin = 100,
 seed = 456)
#> You have specified 0 node level covariate effects.
#> No network covariates provided.
#> Covariates Provided...
#> [1] 1 1 1 1 1 1 1
#> Error in if (GERGM_Object@sample_edges_at_a_time > 0) {: argument is of length zero

sessionInfo()
#> R version 3.6.0 (2019-04-26)
#> Platform: x86_64-pc-linux-gnu (64-bit)
#> Running under: Linux Mint 18.2
#> 
#> Matrix products: default
#> BLAS:   /usr/lib/libblas/libblas.so.3.6.0
#> LAPACK: /usr/lib/lapack/liblapack.so.3.6.0
#> 
#> locale:
#>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
#>  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
#>  [5] LC_MONETARY=fr_FR.UTF-8    LC_MESSAGES=en_US.UTF-8   
#>  [7] LC_PAPER=fr_FR.UTF-8       LC_NAME=C                 
#>  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
#> [11] LC_MEASUREMENT=fr_FR.UTF-8 LC_IDENTIFICATION=C       
#> 
#> attached base packages:
#> [1] stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> other attached packages:
#> [1] GERGM_0.13.0
#> 
#> loaded via a namespace (and not attached):
#>  [1] compiler_3.6.0     plyr_1.8.4         magrittr_1.5      
#>  [4] tools_3.6.0        htmltools_0.3.6    yaml_2.2.0        
#>  [7] Rcpp_1.0.1         stringi_1.4.3      rmarkdown_1.12    
#> [10] highr_0.8          knitr_1.23         stringr_1.4.0     
#> [13] xfun_0.7           digest_0.6.19      RcppParallel_4.4.2
#> [16] evaluate_0.13

^{Created on 2019-05-22 by the reprex package (v0.3.0)}