Invalid inputs FAILED (input.at:102) on Solaris

Hello,

I am trying to uprev bison-3.4.2 to bison-3.7.3 on Solaris. This is the 
only test which fails:

  4: Invalid inputs                                  FAILED (input.at:102)

testsuite.log from case 4 follows:

---<snip>---
#                             -*- compilation -*-
4. input.at:83: testing Invalid inputs ...
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:96: "$PERL" -pi -e 's/\\(\d{3})/chr(oct($1))/ge' input.y || exit 77
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:98: COLUMNS=1000; export COLUMNS; NO_TERM_HYPERLINKS=1; export NO_TERM_HYPERLINKS; VALGRIND_OPTS="$VALGRIND_OPTS --leak-check=summary --show-reachable=no"; export VALGRIND_OPTS;  bison --color=no -fno-caret -fcaret input.y
stderr:
input.y:1.1-2: error: invalid characters: '\0\001\002\377?'
    1 | 
ÿ?
      | ^~
input.y:2.2: error: invalid null character
    2 | ""
      |  ^
input.y:4.1: error: invalid character: '?'
    4 | ?
      | ^
input.y:5.14: error: invalid character: '}'
    5 | default: 'a' }
      |              ^
input.y:6.1: error: invalid character: '%'
    6 | %&
      | ^
input.y:6.2: error: invalid character: '&'
    6 | %&
      |  ^
input.y:7.1-17: error: invalid directive: '%a-does-not-exist'
    7 | %a-does-not-exist
      | ^~~~~~~~~~~~~~~~~
input.y:8.1: error: invalid character: '%'
    8 | %-
      | ^
input.y:8.2: error: invalid character: '-'
    8 | %-
      |  ^
input.y:9.1-10.0: error: missing '%}' at end of file
    9 | %{
      | ^~
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:102: "$PERL" -p -e 's{([\0\377])}{sprintf "\\x%02x", ord($1)}ge' stderr
--- -	2020-11-16 14:37:52.216371958 +0100
+++ /builds/mrehak/workspace/bison/components/bison/build/amd64/tests/testsuite.dir/at-groups/4/stdout	2020-11-16 14:37:52.214908362 +0100
@@ -1,8 +1,8 @@
 input.y:1.1-2: error: invalid characters: '\0\001\002\377?'
-    1 | \x00
\xff?
+    1 | 
\xff?
       | ^~
 input.y:2.2: error: invalid null character
-    2 | "\x00"
+    2 | ""
       |  ^
 input.y:4.1: error: invalid character: '?'
     4 | ?
4. input.at:83: 4. Invalid inputs (input.at:83): FAILED (input.at:102)
---<snip>---

The file is attached as it contains non-printable characters.

This is the input.y:

$ xxd input.y
00000000: 0001 02ff 3f0a 2200 220a 2525 0a3f 0a64  ....?.".".%%.?.d
00000010: 6566 6175 6c74 3a20 2761 2720 7d0a 2526  efault: 'a' }.%&
00000020: 0a25 612d 646f 6573 2d6e 6f74 2d65 7869  .%a-does-not-exi
00000030: 7374 0a25 2d0a 257b 0a                   st.%-.%{.

This test (3) passes on bison-3.4.2. This is stderr from there:

input.y:1.1-2: error: invalid characters: '\0\001\002\377?'
input.y:3.1: error: invalid character: '?'
input.y:4.14: error: invalid character: '}'
input.y:5.1: error: invalid character: '%'
input.y:5.2: error: invalid character: '&'
input.y:6.1-17: error: invalid directive: '%a-does-not-exist'
input.y:7.1: error: invalid character: '%'
input.y:7.2: error: invalid character: '-'
input.y:8.1-9.0: error: missing '%}' at end of file
input.y:8.1-9.0: error: syntax error, unexpected %{...%}

I am not keen on bison, so I would like to ask you for help debugging 
this issue, please. Where should I start, please?

I am not on the list, so reply CCing to [email protected].

Thank you
Martin Rehak

#                             -*- compilation -*-
4. input.at:83: testing Invalid inputs ...
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:96: "$PERL" -pi -e 's/\\(\d{3})/chr(oct($1))/ge' input.y || exit 77
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:98: COLUMNS=1000; export COLUMNS; NO_TERM_HYPERLINKS=1; export NO_TERM_HYPERLINKS; VALGRIND_OPTS="$VALGRIND_OPTS --leak-check=summary --show-reachable=no"; export VALGRIND_OPTS;  bison --color=no -fno-caret -fcaret input.y
stderr:
input.y:1.1-2: error: invalid characters: '\0\001\002\377?'
    1 | 
ÿ?
      | ^~
input.y:2.2: error: invalid null character
    2 | ""
      |  ^
input.y:4.1: error: invalid character: '?'
    4 | ?
      | ^
input.y:5.14: error: invalid character: '}'
    5 | default: 'a' }
      |              ^
input.y:6.1: error: invalid character: '%'
    6 | %&
      | ^
input.y:6.2: error: invalid character: '&'
    6 | %&
      |  ^
input.y:7.1-17: error: invalid directive: '%a-does-not-exist'
    7 | %a-does-not-exist
      | ^~~~~~~~~~~~~~~~~
input.y:8.1: error: invalid character: '%'
    8 | %-
      | ^
input.y:8.2: error: invalid character: '-'
    8 | %-
      |  ^
input.y:9.1-10.0: error: missing '%}' at end of file
    9 | %{
      | ^~
/builds/mrehak/workspace/bison/components/bison/bison-3.7.3/tests/input.at:102: "$PERL" -p -e 's{([\0\377])}{sprintf "\\x%02x", ord($1)}ge' stderr
--- -	2020-11-16 14:37:52.216371958 +0100
+++ /builds/mrehak/workspace/bison/components/bison/build/amd64/tests/testsuite.dir/at-groups/4/stdout	2020-11-16 14:37:52.214908362 +0100
@@ -1,8 +1,8 @@
 input.y:1.1-2: error: invalid characters: '\0\001\002\377?'
-    1 | \x00
\xff?
+    1 | 
\xff?
       | ^~
 input.y:2.2: error: invalid null character
-    2 | "\x00"
+    2 | ""
       |  ^
 input.y:4.1: error: invalid character: '?'
     4 | ?
4. input.at:83: 4. Invalid inputs (input.at:83): FAILED (input.at:102)