ggOceanMaps包绘制地图时经纬度轴度符号缺失，显示方块

使用R语言的ggOceanMaps和ggOceanMapsData包绘制带水深的地图时，经纬度轴标签的度符号无法正常显示，取而代之的是奇怪的方块。无论更换绘图区域、调整代码，还是更新包并重启R，问题都持续存在。

代码示例 #

# 安装包（若未安装）
# devtools::install_github("MikkoVihtakari/ggOceanMapsData")

# 加载依赖库
library(ggOceanMapsData)
library(ggOceanMaps)

# 绘制带水深的基础地图
basemap(limits = c(100, 160, -20, 30), bathymetry = TRUE)

环境信息 #

• 包版本：
  • ggOceanMaps：1.3.4
  • ggOceanMapsData：1.4
• R版本及会话信息：

R version 4.2.2 (2022-10-31 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 22621)
Matrix products: default

locale:
[1] LC_COLLATE=English_United States.utf8 
[2] LC_CTYPE=English_United States.utf8   
[3] LC_MONETARY=English_United States.utf8
[4] LC_NUMERIC=C                           
[5] LC_TIME=English_United States.utf8    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] ggOceanMaps_1.3.4   ggspatial_1.1.6     ggOceanMapsData_1.4
 [4] lubridate_1.9.2     forcats_1.0.0       stringr_1.5.0      
 [7] dplyr_1.1.0         purrr_1.0.1         readr_2.1.4        
[10] tidyr_1.3.0         tibble_3.1.8        ggplot2_3.4.1      
[13] tidyverse_2.0.0    

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.9         pillar_1.8.1       compiler_4.2.2    
 [4] class_7.3-20       tools_4.2.2        lifecycle_1.0.3   
 [7] gtable_0.3.1       timechange_0.2.0   lattice_0.20-45   
[10] pkgconfig_2.0.3    rlang_1.0.6        DBI_1.1.3         
[13] cli_3.6.0          rstudioapi_0.14    parallel_4.2.2    
[16] terra_1.6-17       e1071_1.7-11       raster_3.6-3      
[19] withr_2.5.0        rgeos_0.6-2        generics_0.1.3    
[22] vctrs_0.5.2        hms_1.1.2          classInt_0.4-8    
[25] grid_4.2.2         tidyselect_1.2.0   glue_1.6.2        
[28] sf_1.0-9           R6_2.5.1           fansi_1.0.3       
[31] sp_1.5-0           farver_2.1.1       tzdb_0.3.0        
[34] magrittr_2.0.3     codetools_0.2-18   units_0.8-0       
[37] scales_1.2.1       ellipsis_0.3.2     colorspace_2.0-3  
[40] KernSmooth_2.23-20 utf8_1.2.2         proxy_0.4-27      
[43] stringi_1.7.8      munsell_0.5.0     

R.version
                              
platform       x86_64-w64-mingw32               
arch           x86_64                            
os             mingw32                           
crt            ucrt                              
system         x86_64, mingw32                   
status                                           
major          4                                 
minor          2.2                               
year           2022                              
month          10                                
day            31                                
svn rev        83211                             
language       R                                 
version.string R version 4.2.2 (2022-10-31 ucrt)
nickname       Innocent and Trusting 

补充说明 #

目前已通过其他方法实现了度符号的正常显示，但仍希望了解ggOceanMaps包出现该度符号显示异常（变为方块）的具体原因。

内容的提问来源于stack exchange，提问作者FishyFishies