texlive: fix +letter variant by calling tl-paper

Fixes: https://trac.macports.org/ticket/73590
Fixes: https://trac.macports.org/ticket/62237

tex/texlive/Portfile

@@ -5,7 +5,7 @@ PortGroup       texlive 1.0
 
 name            texlive
 version         2026
-revision        1
+revision        2
 
 categories      tex
 maintainers     {dports @drkp}
@@ -173,7 +173,25 @@ variant full \
 
 variant letter description {Set paper format to letter} {
     post-activate {
-        system "texconfig-sys paper letter"
+        system "${prefix}/bin/tl-paper set all letter && ${prefix}/bin/fmtutil-sys --refresh"
+    }
+
+    # A stale pdftexconfig.tex left over from the legacy texconfig-sys
+    # tool (used by older versions of this variant) lives in TEXMFSYSCONFIG
+    # and will shadow the file tl-paper writes to TEXMFSYSVAR, silently
+    # preventing +letter from taking effect for pdfTeX.  Detect it and
+    # advise the user to remove it; we don't delete it automatically.
+    if {[file exists ${prefix}/etc/texmf/tex/generic/config/pdftexconfig.tex]} {
+        notes-append "
+A stale pdfTeX paper configuration file was found at
+    ${prefix}/etc/texmf/tex/generic/config/pdftexconfig.tex
+left over from a previous run of texconfig-sys.  It will override
+the +letter setting that tl-paper writes, so pdfTeX will not produce
+US Letter output until you remove it:
+
+    sudo rm ${prefix}/etc/texmf/tex/generic/config/pdftexconfig.tex
+    sudo fmtutil-sys --refresh
+"
     }
 }