treewide: refactor `.attrs.sh` detection

When specifying the `builder` attribute in `stdenv.mkDerivation`, this
will be effectively transformed into

    builtins.derivation {
      builder = stdenv.shell;
      args = [ "-e" builder ];
    }

This also means that `default-builder.sh` is never sourced and as a
result it's not guaranteed that `$NIX_ATTRS_SH_FILE` is set to a correct
location[1].

Also, we need to source `.attrs.sh` to source `$stdenv`. So, the
following is done now:

* If `$NIX_ATTRS_SH_FILE` points to a correct location, then use it.
  Directly using `.attrs.sh` is problematic for `nix-shell(1)` usage
  (see previous commit for more context), so prefer the environment
  variable if possible.

* Otherwise, if `.attrs.sh` exists, then use it. See [1] for when this
  can happen.

* If neither applies, it can be assumed that `__structuredAttrs` is
  turned off and thus nothing needs to be done.

[1] It's possible that it doesn't exist at all - in case of Nix 2.3 or
    it can point to a wrong location on older Nix versions with a bug in
    `__structuredAttrs`.

12 files changed, 12 insertions, 12 deletions

diff --git a/pkgs/build-support/fetchbzr/builder.sh b/pkgs/build-support/fetchbzr/builder.sh
index 991864719a0..4515e0e82f4 100644
--- a/pkgs/build-support/fetchbzr/builder.sh
+++ b/pkgs/build-support/fetchbzr/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source "$stdenv/setup"
 
 echo "exporting \`$url' (revision $rev) into \`$out'"
diff --git a/pkgs/build-support/fetchcvs/builder.sh b/pkgs/build-support/fetchcvs/builder.sh
index 4b49e9676ec..7e4dde4a64c 100644
--- a/pkgs/build-support/fetchcvs/builder.sh
+++ b/pkgs/build-support/fetchcvs/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 (echo "#!$SHELL"; \
diff --git a/pkgs/build-support/fetchdarcs/builder.sh b/pkgs/build-support/fetchdarcs/builder.sh
index 75b9066dba6..39838db255a 100644
--- a/pkgs/build-support/fetchdarcs/builder.sh
+++ b/pkgs/build-support/fetchdarcs/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 tagtext=""
diff --git a/pkgs/build-support/fetchdocker/fetchdocker-builder.sh b/pkgs/build-support/fetchdocker/fetchdocker-builder.sh
index 4eb70f672d4..489914a2a8b 100644
--- a/pkgs/build-support/fetchdocker/fetchdocker-builder.sh
+++ b/pkgs/build-support/fetchdocker/fetchdocker-builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source "${stdenv}/setup"
 echo "exporting ${repository}/${imageName} (tag: ${tag}) into ${out}"
 mkdir -p "${out}"
diff --git a/pkgs/build-support/fetchfossil/builder.sh b/pkgs/build-support/fetchfossil/builder.sh
index 36b758ab574..fe828d0ada9 100644
--- a/pkgs/build-support/fetchfossil/builder.sh
+++ b/pkgs/build-support/fetchfossil/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 echo "Cloning Fossil $url [$rev] into $out"
 
diff --git a/pkgs/build-support/fetchgit/builder.sh b/pkgs/build-support/fetchgit/builder.sh
index 77f6381b09a..95176beea8c 100644
--- a/pkgs/build-support/fetchgit/builder.sh
+++ b/pkgs/build-support/fetchgit/builder.sh
@@ -3,7 +3,7 @@
 # - revision specified and remote has a HEAD
 # - revision specified and remote without HEAD
 #
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 echo "exporting $url (rev $rev) into $out"
diff --git a/pkgs/build-support/fetchhg/builder.sh b/pkgs/build-support/fetchhg/builder.sh
index 1ce29475771..20dfde4b10d 100644
--- a/pkgs/build-support/fetchhg/builder.sh
+++ b/pkgs/build-support/fetchhg/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 echo "getting $url${rev:+ ($rev)} into $out"
 
diff --git a/pkgs/build-support/fetchipfs/builder.sh b/pkgs/build-support/fetchipfs/builder.sh
index ca77962b538..1ddd111b151 100644
--- a/pkgs/build-support/fetchipfs/builder.sh
+++ b/pkgs/build-support/fetchipfs/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 # Curl flags to handle redirects, not use EPSV, handle cookies for
diff --git a/pkgs/build-support/fetchmtn/builder.sh b/pkgs/build-support/fetchmtn/builder.sh
index 1aabd7949ee..de929fad55a 100644
--- a/pkgs/build-support/fetchmtn/builder.sh
+++ b/pkgs/build-support/fetchmtn/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 set -x
diff --git a/pkgs/build-support/fetchsvn/builder.sh b/pkgs/build-support/fetchsvn/builder.sh
index aa4d049aba4..e187747f14e 100644
--- a/pkgs/build-support/fetchsvn/builder.sh
+++ b/pkgs/build-support/fetchsvn/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 echo "exporting $url (r$rev) into $out"
diff --git a/pkgs/build-support/fetchsvnssh/builder.sh b/pkgs/build-support/fetchsvnssh/builder.sh
index 5782151524f..e553446346d 100644
--- a/pkgs/build-support/fetchsvnssh/builder.sh
+++ b/pkgs/build-support/fetchsvnssh/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 echo "exporting $url (r$rev) into $out"
diff --git a/pkgs/build-support/fetchurl/builder.sh b/pkgs/build-support/fetchurl/builder.sh
index e8eaba93485..a82728ef102 100644
--- a/pkgs/build-support/fetchurl/builder.sh
+++ b/pkgs/build-support/fetchurl/builder.sh
@@ -1,4 +1,4 @@
-if [ -e .attrs.sh ]; then source .attrs.sh; fi
+if [ -e "$NIX_ATTRS_SH_FILE" ]; then . "$NIX_ATTRS_SH_FILE"; elif [ -f .attrs.sh ]; then . .attrs.sh; fi
 source $stdenv/setup
 
 source $mirrorsFile