Every time I export a manually hinted with autohinting disabled font as OpenType/CFF file I get ttx diffs like this, even when no changes were made to the font:
@@ -3466,7 +3467,7 @@
</CharString>
<CharString name="Abreve">
103 16 -21 237 96 -76 87 328 -20 76 90 129 -20 hstemhm
- 40 110 -7 362 8 112 hintmask 1011111010000000
+ 40 110 -7 362 8 112 hintmask 1101110110000000
625 41 rmoveto
42 -15 9 -10 20 vhcurveto
-27 56 -23 40 -27 62 rrcurveto
@@ -3476,11 +3477,11 @@
5 10 2 11 7 vvcurveto
21 -23 26 -27 -34 -28 -15 -39 -6 vhcurveto
-4 -16 -205 -422 rlineto
+ hintmask 1101111010000000
-27 -55 -12 -34 -32 vvcurveto
-44 43 -15 13 21 33 13 40 vhcurveto
- hintmask 1011110110000000
- 25 -6 7 1 vvcurveto
hintmask 1101110110000000
+ 25 -6 7 1 vvcurveto
18 43 75 29 58 vhcurveto
hintmask 1011110110000000
214 20 23 -46 29 -58 20 -58 rlinecurve
@@ -3560,11 +3561,8 @@
18 43 75 29 58 vhcurveto
hintmask 1011111010000000
214 20 23 -46 29 -58 20 -58 rlinecurve
- hintmask 1011111100000000
6 -18 5 -10 -23 vvcurveto
- -29 27 -15 28 vhcurveto
- hintmask 1011111010000000
- 24 33 26 20 hvcurveto
+ -29 27 -15 28 24 33 26 20 vhcurveto
-454 765 rmoveto
-35 28 -23 32 44 29 40 33 26 -22 41 -42 -47 -22 -46 -36 vhcurveto
hintmask 1101111010000000
This is bad for reproducible builds, and makes tracking actual changes to the exported binary unnecessarily harder. Is this kind of diff expected and is there a way to make the build reproducible?