this derivation will be built:
  /nix/store/h92ivlvj6zn7ajscr4ahjrqkyqkvfj98-treefmt-check.drv
building '/nix/store/h92ivlvj6zn7ajscr4ahjrqkyqkvfj98-treefmt-check.drv'
treefmt-check> tribuchet: building on eliza
treefmt-check> treefmt v2.5.0traversed 56 files
treefmt-check> emitted 40 files for processing
treefmt-check> formatted 40 files (1 changed) in 104ms
treefmt-check>  M shells.nix
treefmt-check> diff --git a/shells.nix b/shells.nix
treefmt-check> index 927bea8..d976ca8 100644
treefmt-check> --- a/shells.nix
treefmt-check> +++ b/shells.nix
treefmt-check> @@ -57,89 +57,111 @@
treefmt-check>    toolchains =
treefmt-check>      let
treefmt-check>        # C/C++ via a stdenv's $CC/$CXX.
treefmt-check> -      mkC = s: "${s.mkDerivation {
treefmt-check> -        name = "fixture";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        buildPhase = "$CC ${./tests/sample.c} -o hello";
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> -      mkCxx = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-cxx";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        buildPhase = "$CXX ${./tests/sample.cpp} -o hello";
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> -      mkRust = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-rust";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        nativeBuildInputs = [ rustc ];
treefmt-check> -        buildPhase = "rustc -O ${./tests/sample.rs} -o hello";
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> +      mkC =
treefmt-check> +        s:
treefmt-check> +        "${
treefmt-check> +          s.mkDerivation {
treefmt-check> +            name = "fixture";
treefmt-check> +            dontUnpack = true;
treefmt-check> +            buildPhase = "$CC ${./tests/sample.c} -o hello";
treefmt-check> +            installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +          }
treefmt-check> +        }/bin/hello";
treefmt-check> +      mkCxx = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-cxx";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          buildPhase = "$CXX ${./tests/sample.cpp} -o hello";
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check> +      mkRust = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-rust";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          nativeBuildInputs = [ rustc ];
treefmt-check> +          buildPhase = "rustc -O ${./tests/sample.rs} -o hello";
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check>        # cgo forces external linking, so the output is dynamic.
treefmt-check> -      mkGo = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-go";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        nativeBuildInputs = [ go ];
treefmt-check> -        buildPhase = ''
treefmt-check> -          export HOME=$TMPDIR GOCACHE=$TMPDIR/gc GO111MODULE=off CGO_ENABLED=1
treefmt-check> -          cp ${./tests/sample.go} main.go
treefmt-check> -          go build -o hello main.go
treefmt-check> -        '';
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> +      mkGo = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-go";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          nativeBuildInputs = [ go ];
treefmt-check> +          buildPhase = ''
treefmt-check> +            export HOME=$TMPDIR GOCACHE=$TMPDIR/gc GO111MODULE=off CGO_ENABLED=1
treefmt-check> +            cp ${./tests/sample.go} main.go
treefmt-check> +            go build -o hello main.go
treefmt-check> +          '';
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check>        # Shared objects: no PT_INTERP, but DT_SONAME, exported dynsym and (C++
treefmt-check>        # via the version script) GNU symbol versions.
treefmt-check> -      mkRustSo = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-rust-cdylib";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        nativeBuildInputs = [ rustc ];
treefmt-check> -        buildPhase = "rustc -O --crate-type=cdylib ${./tests/sample_cdylib.rs} -o libfixture.so";
treefmt-check> -        installPhase = "install -Dm755 libfixture.so $out/lib/libfixture.so";
treefmt-check> -      }}/lib/libfixture.so";
treefmt-check> -      mkCxxSo = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-cxx-so";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        buildPhase = "$CXX -shared -fPIC ${./tests/sample_lib.cpp} -Wl,--version-script=${./tests/sample.map} -Wl,-soname,libfixturecxx.so.1 -o libfixturecxx.so.1";
treefmt-check> -        installPhase = "install -Dm755 libfixturecxx.so.1 $out/lib/libfixturecxx.so.1";
treefmt-check> -      }}/lib/libfixturecxx.so.1";
treefmt-check> -      mkGoSo = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-go-cshared";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        nativeBuildInputs = [ go ];
treefmt-check> -        buildPhase = ''
treefmt-check> -          export HOME=$TMPDIR GOCACHE=$TMPDIR/gc GO111MODULE=off CGO_ENABLED=1
treefmt-check> -          cp ${./tests/sample_cshared.go} main.go
treefmt-check> -          go build -buildmode=c-shared -o libfixture.so main.go
treefmt-check> -        '';
treefmt-check> -        installPhase = "install -Dm755 libfixture.so $out/lib/libfixture.so";
treefmt-check> -      }}/lib/libfixture.so";
treefmt-check> +      mkRustSo = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-rust-cdylib";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          nativeBuildInputs = [ rustc ];
treefmt-check> +          buildPhase = "rustc -O --crate-type=cdylib ${./tests/sample_cdylib.rs} -o libfixture.so";
treefmt-check> +          installPhase = "install -Dm755 libfixture.so $out/lib/libfixture.so";
treefmt-check> +        }
treefmt-check> +      }/lib/libfixture.so";
treefmt-check> +      mkCxxSo = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-cxx-so";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          buildPhase = "$CXX -shared -fPIC ${./tests/sample_lib.cpp} -Wl,--version-script=${./tests/sample.map} -Wl,-soname,libfixturecxx.so.1 -o libfixturecxx.so.1";
treefmt-check> +          installPhase = "install -Dm755 libfixturecxx.so.1 $out/lib/libfixturecxx.so.1";
treefmt-check> +        }
treefmt-check> +      }/lib/libfixturecxx.so.1";
treefmt-check> +      mkGoSo = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-go-cshared";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          nativeBuildInputs = [ go ];
treefmt-check> +          buildPhase = ''
treefmt-check> +            export HOME=$TMPDIR GOCACHE=$TMPDIR/gc GO111MODULE=off CGO_ENABLED=1
treefmt-check> +            cp ${./tests/sample_cshared.go} main.go
treefmt-check> +            go build -buildmode=c-shared -o libfixture.so main.go
treefmt-check> +          '';
treefmt-check> +          installPhase = "install -Dm755 libfixture.so $out/lib/libfixture.so";
treefmt-check> +        }
treefmt-check> +      }/lib/libfixture.so";
treefmt-check>        # Transformation states no compiler flag alone produces:
treefmt-check>        # sstrip drops the section header table entirely, so patchelf must work
treefmt-check>        # from program headers alone; pack-relative-relocs emits DT_RELR;
treefmt-check>        # -fcf-protection adds .note.gnu.property and a PT_GNU_PROPERTY segment.
treefmt-check> -      mkStripped = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-stripped";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        nativeBuildInputs = [ elfkickers ];
treefmt-check> -        buildPhase = ''
treefmt-check> -          $CC ${./tests/sample.c} -o hello
treefmt-check> -          sstrip hello
treefmt-check> -        '';
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> -      mkRelr = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-relr";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        buildPhase = "$CC -O2 -fPIE -pie -Wl,-z,pack-relative-relocs ${./tests/sample_relr.c} -o hello";
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> -      mkGnuProperty = "${stdenv.mkDerivation {
treefmt-check> -        name = "fixture-gnu-property";
treefmt-check> -        dontUnpack = true;
treefmt-check> -        buildPhase = "$CC -fcf-protection=full ${./tests/sample.c} -o hello";
treefmt-check> -        installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> -      }}/bin/hello";
treefmt-check> +      mkStripped = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-stripped";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          nativeBuildInputs = [ elfkickers ];
treefmt-check> +          buildPhase = ''
treefmt-check> +            $CC ${./tests/sample.c} -o hello
treefmt-check> +            sstrip hello
treefmt-check> +          '';
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check> +      mkRelr = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-relr";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          buildPhase = "$CC -O2 -fPIE -pie -Wl,-z,pack-relative-relocs ${./tests/sample_relr.c} -o hello";
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check> +      mkGnuProperty = "${
treefmt-check> +        stdenv.mkDerivation {
treefmt-check> +          name = "fixture-gnu-property";
treefmt-check> +          dontUnpack = true;
treefmt-check> +          buildPhase = "$CC -fcf-protection=full ${./tests/sample.c} -o hello";
treefmt-check> +          installPhase = "install -Dm755 hello $out/bin/hello";
treefmt-check> +        }
treefmt-check> +      }/bin/hello";
treefmt-check>      in
treefmt-check>      mkShell {
treefmt-check>        packages = [
error: Cannot build '/nix/store/h92ivlvj6zn7ajscr4ahjrqkyqkvfj98-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/6mkz05695p8pk89nfi00shr3c4858q31-treefmt-check
       Last 25 log lines:
       > +            $CC ${./tests/sample.c} -o hello
       > +            sstrip hello
       > +          '';
       > +          installPhase = "install -Dm755 hello $out/bin/hello";
       > +        }
       > +      }/bin/hello";
       > +      mkRelr = "${
       > +        stdenv.mkDerivation {
       > +          name = "fixture-relr";
       > +          dontUnpack = true;
       > +          buildPhase = "$CC -O2 -fPIE -pie -Wl,-z,pack-relative-relocs ${./tests/sample_relr.c} -o hello";
       > +          installPhase = "install -Dm755 hello $out/bin/hello";
       > +        }
       > +      }/bin/hello";
       > +      mkGnuProperty = "${
       > +        stdenv.mkDerivation {
       > +          name = "fixture-gnu-property";
       > +          dontUnpack = true;
       > +          buildPhase = "$CC -fcf-protection=full ${./tests/sample.c} -o hello";
       > +          installPhase = "install -Dm755 hello $out/bin/hello";
       > +        }
       > +      }/bin/hello";
       >      in
       >      mkShell {
       >        packages = [
       For full logs, run:
         nix log /nix/store/h92ivlvj6zn7ajscr4ahjrqkyqkvfj98-treefmt-check.drv