Why does sbcl@2.3.7 depends on bash-minimal@5.1.16

[Pan Xie]

Hello

I find this interesting thing but I don't have an explanation. If I 
query the "references" of my store item "sbcl", it shows that sbcl 
reference bash-mininal, as the following output:

# guix gc --references /gnu/store/sbbp9nvslqcf3bmcnz5wgxf2qpsi757$
/gnu/store/6ncav55lbk5kqvwwflrzcr41hp5jbq0c-gcc-11.3.0-lib
/gnu/store/ln6hxqjvz6m9gdd9s97pivlqck7hzs99-glibc-2.35
/gnu/store/mzx7j93w5szyzrgnql8dqhqdgjh6si02-mpfr-4.2.0
/gnu/store/nl194qnq5lhjxpfwcs15xqihnfqif335-zstd-1.5.2-lib
/gnu/store/sbbp9nvslqcf3bmcnz5wgxf2qpsi757i-sbcl-2.3.7
/gnu/store/v9p25q9l5nnaixkhpap5rnymmwbhf9rp-bash-minimal-5.1.16
/gnu/store/ybadavwz1z9kmxanqy3siw38lnkwnkrp-gmp-6.2.1

But when I look into sbcl's package definition, there is no 
"bash-minimal" as its input. I use "guix graph" find a path from sbcl to 
bash-minimal:

# guix graph --path sbcl bash-minimal
sbcl@2.3.7
texlive-updmap.cfg@66594
texlive-scheme-basic@66594
texlive-collection-basic@66594
texlive-bin@20230313
cairo@1.16.0
bash-minimal@5.1.16

But I think that is build time dependency, not run time. cairo also 
requires "ghostscript" as its input, which is not referenced by sbcl.

If I run "guix size sbcl" or "guix pack sbcl", bash-minimal also 
included. I think SBCL might require "sh" to execute some script files,

but I can't figure out how guix decides "bash-minimal" is part of sbcl. 
Would some one please tell me

which part of codes in sbcl's package definition make guix include 
"bash-minimal" into sbcl's references?

Thanks,

Pan