under FreeBSD:

$ sbcl
...

• (ql:quickload :gsll)
  ; pkg-config libffi --cflags
  -I/usr/local/include
  ; cc -o /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel-tmpTZOONXRW.o -c -g -Wall -Wundef -Wsign-compare -Wpointer-arith -O3 -fno-omit-frame-pointer -I/usr/local/include -I/usr/local/include -fPIC -I/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/ /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel.c
  /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel.c:11:7: warning: unused variable 'autotype_tmp' [-Wunused-variable]
  11 | int autotype_tmp;
  | ^~~~~~~~~~~~
  1 warning generated.
  ; cc -o /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel-tmpWN0UKDSV -g -Wl,--export-dynamic /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel.o
  ; /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/libffi/libffi-types__grovel.grovel-tmp.lisp
  To load "gsll":
  Load 1 ASDF system:
  gsll
  ; Loading "gsll"
  [package mgl-pax.asdf]............................
  [package iterate].................................
  [package metabang.bind]...........................
  [package metabang.bind.developer].................
  [package dref-ext]................................
  [package dref]....................................
  [package dref-ext]................................
  [package dref]....................................
  [package mgl-pax].................................
  [package mgl-pax].................................
  [package editor-hints.named-readtables]...........
  [package editor-hints.named-readtables]...........
  [package cl-ppcre]................................
  ..................................................
  [package split-sequence]..........................
  [package lisp-unit]...............................
  [package antik]...................................
  [package grid]....................................
  [package affi]....................................
  [package trivial-garbage].........................
  [package static-vectors]..........................
  [package gsll]; cc -o /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/gsll-quicklisp-eeeda841-git/init/libgsl-unix__grovel-tmpZTS6G7ND.o -c -g -Wall -Wundef -Wsign-compare -Wpointer-arith -O3 -fno-omit-frame-pointer -fPIC -I/usr/local/share/quicklisp/dists/quicklisp/software/cffi-20241012-git/ /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/gsll-quicklisp-eeeda841-git/init/libgsl-unix__grovel.c
  /usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/gsll-quicklisp-eeeda841-git/init/libgsl-unix__grovel.c:6:10: fatal error: 'gsl/gsl_integration.h' file not found
  6 | #include <gsl/gsl_integration.h>
  | ^~~~~~~~~~~~~~~~~~~~~~~
  1 error generated.

debugger invoked on a CFFI-GROVEL:GROVEL-ERROR in thread #<THREAD tid=100343 "main thread" RUNNING {1100B88093}>: Subprocess #<UIOP/LAUNCH-PROGRAM::PROCESS-INFO {11024C9893}>
with command ("cc" "-o" "/usr/home/angel/.cache/common-lisp/sbcl-2.4.9-bsd-x64/usr/local/share/quicklisp/dists/quicklisp/software/gsll-quicklisp-eeeda841-git/init/libgsl-unix__grovel-tmpZTS6G7ND.o" "-c" "-g" "-Wall" "-Wundef" "-Wsign-compare" "-Wpointer-arith" "-O3" "-fno-omit-frame-pointer" "-fPIC" ...)
exited with error code 1

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
0: [RETRY ] Retry # on #<GROVEL-FILE "gsll" "init" "libgsl">.
1: [ACCEPT ] Continue, treating # on #<GROVEL-FILE "gsll" "init" "libgsl"> as having been successful.
2: Retry ASDF operation.
3: [CLEAR-CONFIGURATION-AND-RETRY] Retry ASDF operation after resetting the configuration.
4: Retry ASDF operation.
5: Retry ASDF operation after resetting the configuration.
6: [ABORT ] Give up on "gsll"
7: [REGISTER-LOCAL-PROJECTS ] Register local projects and try again.
8: Exit debugger, returning to top level.

(CFFI-GROVEL:GROVEL-ERROR "~a" #<UIOP/RUN-PROGRAM:SUBPROCESS-ERROR {1102505E73}>)
source: (ERROR (QUOTE GROVEL-ERROR) :FORMAT-CONTROL FORMAT-CONTROL :FORMAT-ARGUMENTS FORMAT-ARGUMENTS)
0]