diff --git a/spec/core_functions/math/atan2/arguments.hrx b/spec/core_functions/math/atan2/arguments.hrx
index 8b36e2a89c..9e7ccc93ad 100644
--- a/spec/core_functions/math/atan2/arguments.hrx
+++ b/spec/core_functions/math/atan2/arguments.hrx
@@ -1,5 +1,3 @@
-<===>
-================================================================================
 <===> named_args/input.scss
 @use "sass:math" as math;
 a {b: math.atan2($y: 1, $x: -1)}
@@ -55,7 +53,7 @@ Error: $x: "0" is not a number.
 a {b: math.atan2(1px, 1deg)}
 
 <===> error/incompatible_units/error
-Error: Incompatible units deg and px.
+Error: $x: 1deg and $y: 1px have incompatible units.
   ,
 2 | a {b: math.atan2(1px, 1deg)}
   |       ^^^^^^^^^^^^^^^^^^^^^
@@ -69,7 +67,7 @@ Error: Incompatible units deg and px.
 a {b: math.atan2(1, 1px)}
 
 <===> error/unitless_y/error
-Error: $y is unitless but $x has unit px. Arguments must all have units or all be unitless.
+Error: $x: 1px and $y: 1 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.atan2(1, 1px)}
   |       ^^^^^^^^^^^^^^^^^^
@@ -83,7 +81,7 @@ Error: $y is unitless but $x has unit px. Arguments must all have units or all b
 a {b: math.atan2(1px, 1)}
 
 <===> error/unitless_x/error
-Error: $y has unit px but $x is unitless. Arguments must all have units or all be unitless.
+Error: $x: 1 and $y: 1px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.atan2(1px, 1)}
   |       ^^^^^^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/clamp.hrx b/spec/core_functions/math/clamp.hrx
index a652d980ea..3af6ec3ea6 100644
--- a/spec/core_functions/math/clamp.hrx
+++ b/spec/core_functions/math/clamp.hrx
@@ -155,7 +155,7 @@ Error: $max: "0" is not a number.
 a {b: math.clamp(1deg, 1px, 1turn)}
 
 <===> error/incompatible_units/min_and_number/error
-Error: Incompatible units px and deg.
+Error: $number: 1px and $min: 1deg have incompatible units.
   ,
 2 | a {b: math.clamp(1deg, 1px, 1turn)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -169,7 +169,7 @@ Error: Incompatible units px and deg.
 a {b: math.clamp(1deg, 1turn, 1px)}
 
 <===> error/incompatible_units/min_and_max/error
-Error: Incompatible units px and deg.
+Error: $max: 1px and $min: 1deg have incompatible units.
   ,
 2 | a {b: math.clamp(1deg, 1turn, 1px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -183,7 +183,7 @@ Error: Incompatible units px and deg.
 a {b: math.clamp(1turn, 1deg, 1px)}
 
 <===> error/incompatible_units/number_and_max/error
-Error: Incompatible units px and turn.
+Error: $max: 1px and $min: 1turn have incompatible units.
   ,
 2 | a {b: math.clamp(1turn, 1deg, 1px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -197,7 +197,7 @@ Error: Incompatible units px and turn.
 a {b: math.clamp(1deg, 1px, 1s)}
 
 <===> error/incompatible_units/all/error
-Error: Incompatible units s and deg.
+Error: $number: 1px and $min: 1deg have incompatible units.
   ,
 2 | a {b: math.clamp(1deg, 1px, 1s)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -211,7 +211,7 @@ Error: Incompatible units s and deg.
 a {b: math.clamp(0, 1px, 2px)}
 
 <===> error/some_unitless/min/error
-Error: $min is unitless but $number has unit px. Arguments must all have units or all be unitless.
+Error: $number: 1px and $min: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0, 1px, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -225,7 +225,7 @@ Error: $min is unitless but $number has unit px. Arguments must all have units o
 a {b: math.clamp(0px, 1, 2px)}
 
 <===> error/some_unitless/number/error
-Error: $min has unit px but $number is unitless. Arguments must all have units or all be unitless.
+Error: $number: 1 and $min: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0px, 1, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -239,7 +239,7 @@ Error: $min has unit px but $number is unitless. Arguments must all have units o
 a {b: math.clamp(0px, 1px, 2)}
 
 <===> error/some_unitless/max/error
-Error: $min has unit px but $max is unitless. Arguments must all have units or all be unitless.
+Error: $max: 2 and $min: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0px, 1px, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -253,7 +253,7 @@ Error: $min has unit px but $max is unitless. Arguments must all have units or a
 a {b: math.clamp(0, 1, 2px)}
 
 <===> error/some_unitless/min_and_number/error
-Error: $min is unitless but $max has unit px. Arguments must all have units or all be unitless.
+Error: $max: 2px and $min: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0, 1, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^
@@ -267,7 +267,7 @@ Error: $min is unitless but $max has unit px. Arguments must all have units or a
 a {b: math.clamp(0, 1px, 2)}
 
 <===> error/some_unitless/min_and_max/error
-Error: $min is unitless but $number has unit px. Arguments must all have units or all be unitless.
+Error: $number: 1px and $min: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0, 1px, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^
@@ -281,7 +281,7 @@ Error: $min is unitless but $number has unit px. Arguments must all have units o
 a {b: math.clamp(0px, 1, 2)}
 
 <===> error/some_unitless/number_and_max/error
-Error: $min has unit px but $number is unitless. Arguments must all have units or all be unitless.
+Error: $number: 1 and $min: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.clamp(0px, 1, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/cos.hrx b/spec/core_functions/math/cos.hrx
index 47eda337b0..7ec638d255 100644
--- a/spec/core_functions/math/cos.hrx
+++ b/spec/core_functions/math/cos.hrx
@@ -112,7 +112,7 @@ Error: $number: "0" is not a number.
 a {b: math.cos(1px)}
 
 <===> error/unit/error
-Error: $number: Expected 1px to be an angle.
+Error: $number: Expected 1px to have an angle unit (deg, grad, rad, turn).
   ,
 2 | a {b: math.cos(1px)}
   |       ^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/hypot.hrx b/spec/core_functions/math/hypot.hrx
index b9fcebb6e3..32f5f4b204 100644
--- a/spec/core_functions/math/hypot.hrx
+++ b/spec/core_functions/math/hypot.hrx
@@ -107,7 +107,7 @@ Error: "0" is not a number.
 a {b: math.hypot(1deg, 1px, 1turn)}
 
 <===> error/incompatible_units/first_and_second/error
-Error: Incompatible units px and deg.
+Error: $numbers[2]: 1px and $numbers[1]: 1deg have incompatible units.
   ,
 2 | a {b: math.hypot(1deg, 1px, 1turn)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -121,7 +121,7 @@ Error: Incompatible units px and deg.
 a {b: math.hypot(1deg, 1turn, 1px)}
 
 <===> error/incompatible_units/first_and_third/error
-Error: Incompatible units px and deg.
+Error: $numbers[3]: 1px and $numbers[1]: 1deg have incompatible units.
   ,
 2 | a {b: math.hypot(1deg, 1turn, 1px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -135,7 +135,7 @@ Error: Incompatible units px and deg.
 a {b: math.hypot(1turn, 1deg, 1px)}
 
 <===> error/incompatible_units/second_and_third/error
-Error: Incompatible units px and turn.
+Error: $numbers[3]: 1px and $numbers[1]: 1turn have incompatible units.
   ,
 2 | a {b: math.hypot(1turn, 1deg, 1px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -149,7 +149,7 @@ Error: Incompatible units px and turn.
 a {b: math.hypot(1turn, 1px, 1s)}
 
 <===> error/incompatible_units/all/error
-Error: Incompatible units px and turn.
+Error: $numbers[2]: 1px and $numbers[1]: 1turn have incompatible units.
   ,
 2 | a {b: math.hypot(1turn, 1px, 1s)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -163,7 +163,7 @@ Error: Incompatible units px and turn.
 a {b: math.hypot(0, 1px, 2px)}
 
 <===> error/some_unitless/first/error
-Error: Argument 1 is unitless but argument 2 has unit px. Arguments must all have units or all be unitless.
+Error: $numbers[2]: 1px and $numbers[1]: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0, 1px, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -177,7 +177,7 @@ Error: Argument 1 is unitless but argument 2 has unit px. Arguments must all hav
 a {b: math.hypot(0px, 1, 2px)}
 
 <===> error/some_unitless/second/error
-Error: Argument 1 has unit px but argument 2 is unitless. Arguments must all have units or all be unitless.
+Error: $numbers[2]: 1 and $numbers[1]: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0px, 1, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -191,7 +191,7 @@ Error: Argument 1 has unit px but argument 2 is unitless. Arguments must all hav
 a {b: math.hypot(0px, 1px, 2)}
 
 <===> error/some_unitless/third/error
-Error: Argument 1 has unit px but argument 3 is unitless. Arguments must all have units or all be unitless.
+Error: $numbers[3]: 2 and $numbers[1]: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0px, 1px, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^^^
@@ -205,7 +205,7 @@ Error: Argument 1 has unit px but argument 3 is unitless. Arguments must all hav
 a {b: math.hypot(0, 1, 2px)}
 
 <===> error/some_unitless/first_and_second/error
-Error: Argument 1 is unitless but argument 3 has unit px. Arguments must all have units or all be unitless.
+Error: $numbers[3]: 2px and $numbers[1]: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0, 1, 2px)}
   |       ^^^^^^^^^^^^^^^^^^^^^
@@ -219,7 +219,7 @@ Error: Argument 1 is unitless but argument 3 has unit px. Arguments must all hav
 a {b: math.hypot(0, 1px, 2)}
 
 <===> error/some_unitless/first_and_third/error
-Error: Argument 1 is unitless but argument 2 has unit px. Arguments must all have units or all be unitless.
+Error: $numbers[2]: 1px and $numbers[1]: 0 have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0, 1px, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^
@@ -233,7 +233,7 @@ Error: Argument 1 is unitless but argument 2 has unit px. Arguments must all hav
 a {b: math.hypot(0px, 1, 2)}
 
 <===> error/some_unitless/second_and_third/error
-Error: Argument 1 has unit px but argument 2 is unitless. Arguments must all have units or all be unitless.
+Error: $numbers[2]: 1 and $numbers[1]: 0px have incompatible units (one has units and the other doesn't).
   ,
 2 | a {b: math.hypot(0px, 1, 2)}
   |       ^^^^^^^^^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/max.hrx b/spec/core_functions/math/max.hrx
index 533a8673e2..426e182f79 100644
--- a/spec/core_functions/math/max.hrx
+++ b/spec/core_functions/math/max.hrx
@@ -155,7 +155,7 @@ a {b: max($arg, 2s)}
 
 
 <===> error/incompatible_units/error
-Error: Incompatible units s and px.
+Error: 2s and 1px have incompatible units.
   ,
 2 | a {b: max($arg, 2s)}
   |       ^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/min.hrx b/spec/core_functions/math/min.hrx
index f51c2afa94..9e15ab832d 100644
--- a/spec/core_functions/math/min.hrx
+++ b/spec/core_functions/math/min.hrx
@@ -154,7 +154,7 @@ $arg: 1px;
 a {b: min($arg, 2s)}
 
 <===> error/incompatible_units/error
-Error: Incompatible units s and px.
+Error: 2s and 1px have incompatible units.
   ,
 2 | a {b: min($arg, 2s)}
   |       ^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/sin.hrx b/spec/core_functions/math/sin.hrx
index f42fd48f73..53863caeae 100644
--- a/spec/core_functions/math/sin.hrx
+++ b/spec/core_functions/math/sin.hrx
@@ -156,7 +156,7 @@ Error: $number: "0" is not a number.
 a {b: math.sin(1px)}
 
 <===> error/unit/error
-Error: $number: Expected 1px to be an angle.
+Error: $number: Expected 1px to have an angle unit (deg, grad, rad, turn).
   ,
 2 | a {b: math.sin(1px)}
   |       ^^^^^^^^^^^^^
diff --git a/spec/core_functions/math/tan.hrx b/spec/core_functions/math/tan.hrx
index b7b0650dc0..ed57d8a429 100644
--- a/spec/core_functions/math/tan.hrx
+++ b/spec/core_functions/math/tan.hrx
@@ -178,7 +178,7 @@ Error: $number: "0" is not a number.
 a {b: math.tan(1px)}
 
 <===> error/unit/error
-Error: $number: Expected 1px to be an angle.
+Error: $number: Expected 1px to have an angle unit (deg, grad, rad, turn).
   ,
 2 | a {b: math.tan(1px)}
   |       ^^^^^^^^^^^^^
diff --git a/spec/core_functions/meta/load_css/error.hrx b/spec/core_functions/meta/load_css/error.hrx
index 545779afd4..136045dc62 100644
--- a/spec/core_functions/meta/load_css/error.hrx
+++ b/spec/core_functions/meta/load_css/error.hrx
@@ -531,7 +531,7 @@ Error: Expected expression.
 a {b: 1px + 1em}
 
 <===> from_other/runtime/error
-Error: Incompatible units em and px.
+Error: 1em and 1px have incompatible units.
   ,
 1 | a {b: 1px + 1em}
   |       ^^^^^^^^^
diff --git a/spec/directives/forward/error/with.hrx b/spec/directives/forward/error/with.hrx
index 4582b21308..ea61f6c965 100644
--- a/spec/directives/forward/error/with.hrx
+++ b/spec/directives/forward/error/with.hrx
@@ -127,7 +127,7 @@ Error: This variable is available from multiple global modules.
 $a: c !default;
 
 <===> invalid_expression/error/error
-Error: Incompatible units em and px.
+Error: 1em and 1px have incompatible units.
   ,
 1 | @forward "upstream" with ($a: 1px + 1em);
   |                               ^^^^^^^^^
diff --git a/spec/directives/use/error/with.hrx b/spec/directives/use/error/with.hrx
index 0c89bb7e4f..7a55570dcc 100644
--- a/spec/directives/use/error/with.hrx
+++ b/spec/directives/use/error/with.hrx
@@ -104,7 +104,7 @@ Error: This variable is available from multiple global modules.
 $a: c !default;
 
 <===> invalid_expression/error/error
-Error: Incompatible units em and px.
+Error: 1em and 1px have incompatible units.
   ,
 1 | @use "other" with ($a: 1px + 1em);
   |                        ^^^^^^^^^
diff --git a/spec/libsass-closed-issues/issue_1577.hrx b/spec/libsass-closed-issues/issue_1577.hrx
index e792cac1e5..11022915de 100644
--- a/spec/libsass-closed-issues/issue_1577.hrx
+++ b/spec/libsass-closed-issues/issue_1577.hrx
@@ -4,14 +4,14 @@ $foo: 10%; // line 1
 $error: $foo + 20px; // line 3
 
 <===> error
-Error: Incompatible units: 'px' and '%'.
-        on line 3 of input.scss
-  Use --trace for backtrace.
-
-<===> error-dart-sass
-Error: Incompatible units px and %.
+Error: 20px and 10% have incompatible units.
   ,
 3 | $error: $foo + 20px; // line 3
   |         ^^^^^^^^^^^
   '
   input.scss 3:9  root stylesheet
+
+<===> error-libsass
+Error: Incompatible units: 'px' and '%'.
+        on line 3 of input.scss
+  Use --trace for backtrace.
diff --git a/spec/non_conformant/errors/for-incompatible-units-fn.hrx b/spec/non_conformant/errors/for-incompatible-units-fn.hrx
index 0ebc518483..72fe1e9568 100644
--- a/spec/non_conformant/errors/for-incompatible-units-fn.hrx
+++ b/spec/non_conformant/errors/for-incompatible-units-fn.hrx
@@ -5,15 +5,15 @@
 
 foo { bar: test(); }
 <===> error
-Error: Incompatible units: 'px' and '%'.
-        on line 2 of input.scss
-  Use --trace for backtrace.
-
-<===> error-dart-sass
-Error: Incompatible units % and px.
+Error: Expected 100% to have a length unit (in, cm, pc, mm, q, pt, px).
   ,
 2 |   @for $i from 100% through 42px {}
   |                ^^^^
   '
   input.scss 2:16  test()
   input.scss 5:12  root stylesheet
+
+<===> error-libsass
+Error: Incompatible units: 'px' and '%'.
+        on line 2 of input.scss
+  Use --trace for backtrace.
diff --git a/spec/non_conformant/errors/for-incompatible-units.hrx b/spec/non_conformant/errors/for-incompatible-units.hrx
index 7eca0572b1..d29b3c5f49 100644
--- a/spec/non_conformant/errors/for-incompatible-units.hrx
+++ b/spec/non_conformant/errors/for-incompatible-units.hrx
@@ -1,12 +1,7 @@
 <===> input.scss
 @for $i from 100% through 42px {}
 <===> error
-Error: Incompatible units: 'px' and '%'.
-        on line 1 of input.scss
-  Use --trace for backtrace.
-
-<===> error-dart-sass
-Error: Incompatible units % and px.
+Error: Expected 100% to have a length unit (in, cm, pc, mm, q, pt, px).
   ,
 1 | @for $i from 100% through 42px {}
   |              ^^^^
diff --git a/spec/non_conformant/errors/invalid-operation/sub.hrx b/spec/non_conformant/errors/invalid-operation/sub.hrx
index 8b199d3768..599f57bc79 100644
--- a/spec/non_conformant/errors/invalid-operation/sub.hrx
+++ b/spec/non_conformant/errors/invalid-operation/sub.hrx
@@ -3,14 +3,9 @@ test {
   err: 2px - 2px*2px;
 }
 <===> error
-Error: Incompatible units: 'px' and ''.
-        on line 2 of input.scss
-  Use --trace for backtrace.
-
-<===> error-dart-sass
-Error: Incompatible units px*px and px.
+Error: 4px*px and 2px have incompatible units.
   ,
-2 |   err: 2px - 2px*2px;
+2 |   err: 2px - 2px*2px;
   |        ^^^^^^^^^^^^^
   '
   input.scss 2:8  root stylesheet