$  esy install && esy build
info install 0.5.6 (using package.json)
info esy build 0.5.6 (using package.json)
info building esy-sdl2@2.0.10001@d41d8cd9
info building esy-sdl2@2.0.10001@d41d8cd9: done
    ocamlopt src/reglfw.cmxs (exit 2)
(cd /home/sawyer/reason/reason-sdl2/_esy/default/store/b/reason_glfw-f1e788cf/default && /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/bin/ocamlopt.opt -w @a-4-29-40-41-42-44-45-48-58-59-60-40 -strict-sequence -strict-formats -short-paths -keep-locs -g -shared -linkall -I src -o src/reglfw.cmxs src/reglfw.cmxa)
/usr/bin/ld: cannot find -lsdl2
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking
    ocamlopt test/test.exe (exit 2)
(cd /home/sawyer/reason/reason-sdl2/_esy/default/store/b/reason_glfw-f1e788cf/default && /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/bin/ocamlopt.opt -w @a-4-29-40-41-42-44-45-48-58-59-60-40 -strict-sequence -strict-formats -short-paths -keep-locs -g -o test/test.exe -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__ocamlfind-opam__c__1.8.1-034b46eb/lib/bytes -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__seq-opam__c__base-37652505/lib/seq -I /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm -I src /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result/result.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt/lwt.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm/reglm.cmxa src/reglfw.cmxa test/.test.eobjs/native/test.cmx)
/usr/bin/ld: cannot find -lsdl2
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking
    ocamlopt bin_js/test_glfw.exe (exit 2)
(cd /home/sawyer/reason/reason-sdl2/_esy/default/store/b/reason_glfw-f1e788cf/default && /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/bin/ocamlopt.opt -w @a-4-29-40-41-42-44-45-48-58-59-60-40 -strict-sequence -strict-formats -short-paths -keep-locs -g -o bin_js/test_glfw.exe -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__js__of__ocaml-opam__c__3.4.0-1b3a239f/lib/js_of_ocaml -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__ocamlfind-opam__c__1.8.1-034b46eb/lib/bytes -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__seq-opam__c__base-37652505/lib/seq -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__uchar-opam__c__0.0.2-a0257ecf/lib/uchar -I /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm -I examples -I src /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result/result.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt/lwt.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__js__of__ocaml-opam__c__3.4.0-1b3a239f/lib/js_of_ocaml/js_of_ocaml.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/unix.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/bigarray.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm/reglm.cmxa src/reglfw.cmxa examples/EsyGlfwExamples.cmxa bin_js/.test_glfw.eobjs/native/test_glfw.cmx)
/usr/bin/ld: cannot find -lsdl2
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking
    ocamlopt bin_native/test_glfw.exe (exit 2)
(cd /home/sawyer/reason/reason-sdl2/_esy/default/store/b/reason_glfw-f1e788cf/default && /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/bin/ocamlopt.opt -w @a-4-29-40-41-42-44-45-48-58-59-60-40 -strict-sequence -strict-formats -short-paths -keep-locs -g -o bin_native/test_glfw.exe -I /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/threads -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt/unix -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__mmap-opam__c__1.1.0-bdb1a651/lib/mmap -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__ocamlfind-opam__c__1.8.1-034b46eb/lib/bytes -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result -I /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__seq-opam__c__base-37652505/lib/seq -I /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm -I examples -I src /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__result-opam__c__1.4-b0decc79/lib/result/result.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt/lwt.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/unix.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/bigarray.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__mmap-opam__c__1.1.0-bdb1a651/lib/mmap/mmap.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/ocaml-4.7.1004-a6ae015e/lib/ocaml/threads/threads.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/opam__s__lwt-opam__c__4.2.1-5ddb195a/lib/lwt/unix/lwt_unix.cmxa /home/sawyer/.esy/3___________________________________________________________________/i/reason_gl_matrix-0.9.9304-83d48c80/lib/reglm/reglm.cmxa src/reglfw.cmxa examples/EsyGlfwExamples.cmxa bin_native/.test_glfw.eobjs/native/test_glfw.cmx)
/usr/bin/ld: cannot find -lsdl2
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking
error: command failed: 'dune' 'build' '--root' '.' (exited with 1)
esy-build-package: exiting with errors above...
error: build failed with exit code: 1

esy: exiting due to errors above