Closed
Description
rustc does not emit color output when running under a tmux session with TERM set correctly to tmux-256color (supported by the latest versions of ncurses) even with cargo +nightly build --color=always when TERM is set to tmux-256color. On the machine in question (macOS) the term file for tmux-256color is installed and infocmp returns the following:
# Reconstructed via infocmp from file: /usr/local/Cellar/ncurses/6.0_4/share/terminfo/74/tmux-256color
tmux-256color|tmux with 256 colors,
am, hs, km, mir, msgr, xenl,
colors#0x100, cols#80, it#8, lines#24, pairs#0x7fff,
acsc=++\,\,--..00``aaffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, civis=\E[?25l,
clear=\E[H\E[J, cnorm=\E[34h\E[?25h, cr=\r,
csr=\E[%i%p1%d;%p2%dr, cub=\E[%p1%dD, cub1=^H,
cud=\E[%p1%dB, cud1=\n, cuf=\E[%p1%dC, cuf1=\E[C,
cup=\E[%i%p1%d;%p2%dH, cuu=\E[%p1%dA, cuu1=\EM,
cvvis=\E[34l, dch=\E[%p1%dP, dch1=\E[P, dim=\E[2m,
dl=\E[%p1%dM, dl1=\E[M, dsl=\E]0;\007, ed=\E[J, el=\E[K,
el1=\E[1K, enacs=\E(B\E)0, flash=\Eg, fsl=^G, home=\E[H,
ht=^I, hts=\EH, ich=\E[%p1%d@, il=\E[%p1%dL, il1=\E[L,
ind=\n, is2=\E)0, kDC=\E[3;2~, kEND=\E[1;2F, kHOM=\E[1;2H,
kIC=\E[2;2~, kLFT=\E[1;2D, kNXT=\E[6;2~, kPRV=\E[5;2~,
kRIT=\E[1;2C, kbs=^H, kcbt=\E[Z, kcub1=\EOD, kcud1=\EOB,
kcuf1=\EOC, kcuu1=\EOA, kdch1=\E[3~, kend=\E[4~, kf1=\EOP,
kf10=\E[21~, kf11=\E[23~, kf12=\E[24~, kf13=\E[1;2P,
kf14=\E[1;2Q, kf15=\E[1;2R, kf16=\E[1;2S, kf17=\E[15;2~,
kf18=\E[17;2~, kf19=\E[18;2~, kf2=\EOQ, kf20=\E[19;2~,
kf21=\E[20;2~, kf22=\E[21;2~, kf23=\E[23;2~,
kf24=\E[24;2~, kf25=\E[1;5P, kf26=\E[1;5Q, kf27=\E[1;5R,
kf28=\E[1;5S, kf29=\E[15;5~, kf3=\EOR, kf30=\E[17;5~,
kf31=\E[18;5~, kf32=\E[19;5~, kf33=\E[20;5~,
kf34=\E[21;5~, kf35=\E[23;5~, kf36=\E[24;5~,
kf37=\E[1;6P, kf38=\E[1;6Q, kf39=\E[1;6R, kf4=\EOS,
kf40=\E[1;6S, kf41=\E[15;6~, kf42=\E[17;6~,
kf43=\E[18;6~, kf44=\E[19;6~, kf45=\E[20;6~,
kf46=\E[21;6~, kf47=\E[23;6~, kf48=\E[24;6~,
kf49=\E[1;3P, kf5=\E[15~, kf50=\E[1;3Q, kf51=\E[1;3R,
kf52=\E[1;3S, kf53=\E[15;3~, kf54=\E[17;3~,
kf55=\E[18;3~, kf56=\E[19;3~, kf57=\E[20;3~,
kf58=\E[21;3~, kf59=\E[23;3~, kf6=\E[17~, kf60=\E[24;3~,
kf61=\E[1;4P, kf62=\E[1;4Q, kf63=\E[1;4R, kf7=\E[18~,
kf8=\E[19~, kf9=\E[20~, khome=\E[1~, kich1=\E[2~,
kind=\E[1;2B, kmous=\E[M, knp=\E[6~, kpp=\E[5~,
kri=\E[1;2A, nel=\EE, op=\E[39;49m, rc=\E8, rev=\E[7m,
ri=\EM, ritm=\E[23m, rmacs=^O, rmcup=\E[?1049l, rmir=\E[4l,
rmkx=\E[?1l\E>, rmso=\E[27m, rmul=\E[24m,
rs2=\Ec\E[?1000l\E[?25h, sc=\E7,
setab=\E[%?%p1%{8}%<%t4%p1%d%e%p1%{16}%<%t10%p1%{8}%-%d%e48;5;%p1%d%;m,
setaf=\E[%?%p1%{8}%<%t3%p1%d%e%p1%{16}%<%t9%p1%{8}%-%d%e38;5;%p1%d%;m,
sgr=\E[0%?%p6%t;1%;%?%p1%t;3%;%?%p2%t;4%;%?%p3%t;7%;%?%p4%t;5%;%?%p5%t;2%;m%?%p9%t\016%e\017%;,
sgr0=\E[m\017, sitm=\E[3m, smacs=^N, smcup=\E[?1049h,
smir=\E[4h, smkx=\E[?1h\E=, smso=\E[7m, smul=\E[4m,
tbc=\E[3g, tsl=\E]0;,
Per rust-lang/cargo#2877 cargo should be invoking rustc with the --color always flag, and indeed, cargo rustc --color always -- --color always returns 'Option color given more than once`.
Executing env TERM=xterm-256color cargo build also does not produce color output, but env TERM=xterm-256color cargo build --color always does.