Function as.bigq() causing R session to crash

Entering, e.g., gmp::as.bigq(3) will deliver the following error message:

*** caught illegal operation ***
address 0x10d320f80, cause 'illegal opcode'

A minimal code example that reproduces the bug:

library(gmp)
gmp::as.bigq(3)

Output

 *** caught illegal operation ***
address 0x10d320f80, cause 'illegal opcode'

Traceback:
 1: gmp::as.bigq(3)

Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace

Version

> sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Catalina 10.15.7

Matrix products: default
BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib

locale:
[1] C/UTF-8/C/C/C/C

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

other attached packages:
[1] gmp_0.6-0

loaded via a namespace (and not attached):
[1] compiler_4.0.2